diff --git a/Assets/YooAsset/Runtime/CacheSystem/PersistentTools.cs b/Assets/YooAsset/Runtime/CacheSystem/PersistentTools.cs
index 407da3f..1a9941b 100644
--- a/Assets/YooAsset/Runtime/CacheSystem/PersistentTools.cs
+++ b/Assets/YooAsset/Runtime/CacheSystem/PersistentTools.cs
@@ -5,6 +5,7 @@ namespace YooAsset
 {
 	internal static class PersistentTools
 	{
+		private const string SandboxFolderName = "Sandbox";
 		private const string CacheFolderName = "CacheFiles";
 		private const string CachedBundleFileFolder = "BundleFiles";
 		private const string CachedRawFileFolder = "RawFiles";
@@ -33,27 +34,23 @@ namespace YooAsset
 			if (string.IsNullOrEmpty(_sandboxPath))
 			{
 				string projectPath = Path.GetDirectoryName(UnityEngine.Application.dataPath);
-				_sandboxPath = Path.Combine(projectPath, "Sandbox");
+				projectPath = PathUtility.RegularPath(projectPath);
+				_sandboxPath = PathUtility.Combine(projectPath, SandboxFolderName);
 			}
 #elif UNITY_STANDALONE
 			if (string.IsNullOrEmpty(_sandboxPath))
 			{
-				_sandboxPath = Path.Combine(UnityEngine.Application.dataPath, "Sandbox");
+				_sandboxPath = PathUtility.Combine(UnityEngine.Application.dataPath, SandboxFolderName);
 			}
 #else
 			if (string.IsNullOrEmpty(_sandboxPath))
 			{
-				_sandboxPath = Path.Combine(UnityEngine.Application.persistentDataPath, "Sandbox");
+				_sandboxPath = PathUtility.Combine(UnityEngine.Application.persistentDataPath, SandboxFolderName);
 			}
 #endif
 
 			return _sandboxPath;
 		}
-		private static string GetRegularPath(string path)
-		{
-			return path.Replace('\\', '/').Replace("\\", "/"); //替换为Linux路径格式
-		}
-
 
 		/// <summary>
 		/// 获取基于流文件夹的加载路径
@@ -62,9 +59,9 @@ namespace YooAsset
 		{
 			if (string.IsNullOrEmpty(_buildinPath))
 			{
-				_buildinPath = Path.Combine(UnityEngine.Application.streamingAssetsPath, YooAssetSettings.StreamingAssetsBuildinFolder);
+				_buildinPath = PathUtility.Combine(UnityEngine.Application.streamingAssetsPath, YooAssetSettings.StreamingAssetsBuildinFolder);
 			}
-			return Path.Combine(_buildinPath, path);
+			return PathUtility.Combine(_buildinPath, path);
 		}
 
 		/// <summary>
@@ -73,17 +70,17 @@ namespace YooAsset
 		public static string MakePersistentLoadPath(string path)
 		{
 			string root = GetPersistentRootPath();
-			return Path.Combine(root, path);
+			return PathUtility.Combine(root, path);
 		}
 		public static string MakePersistentLoadPath(string path1, string path2)
 		{
 			string root = GetPersistentRootPath();
-			return Path.Combine(root, path1, path2);
+			return PathUtility.Combine(root, path1, path2);
 		}
 		public static string MakePersistentLoadPath(string path1, string path2, string path3)
 		{
 			string root = GetPersistentRootPath();
-			return Path.Combine(root, path1, path2, path3);
+			return PathUtility.Combine(root, path1, path2, path3);
 		}
 
 		/// <summary>
diff --git a/Assets/YooAsset/Runtime/PackageSystem/PackageBundle.cs b/Assets/YooAsset/Runtime/PackageSystem/PackageBundle.cs
index 2dac595..60a9d8e 100644
--- a/Assets/YooAsset/Runtime/PackageSystem/PackageBundle.cs
+++ b/Assets/YooAsset/Runtime/PackageSystem/PackageBundle.cs
@@ -75,13 +75,13 @@ namespace YooAsset
 				if (IsRawFile)
 				{
 					string cacheRoot = PersistentTools.GetCachedRawFileFolderPath(PackageName);
-					_cachedDataFilePath = System.IO.Path.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleDataFileName);
+					_cachedDataFilePath = PathUtility.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleDataFileName);
 					_cachedDataFilePath += _fileExtension;
 				}
 				else
 				{
 					string cacheRoot = PersistentTools.GetCachedBundleFileFolderPath(PackageName);
-					_cachedDataFilePath = System.IO.Path.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleDataFileName);
+					_cachedDataFilePath = PathUtility.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleDataFileName);
 				}
 				return _cachedDataFilePath;
 			}
@@ -102,12 +102,12 @@ namespace YooAsset
 				if (IsRawFile)
 				{
 					string cacheRoot = PersistentTools.GetCachedRawFileFolderPath(PackageName);
-					_cachedInfoFilePath = System.IO.Path.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleInfoFileName);
+					_cachedInfoFilePath = PathUtility.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleInfoFileName);
 				}
 				else
 				{
 					string cacheRoot = PersistentTools.GetCachedBundleFileFolderPath(PackageName);
-					_cachedInfoFilePath = System.IO.Path.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleInfoFileName);
+					_cachedInfoFilePath = PathUtility.Combine(cacheRoot, folderName, CacheGUID, YooAssetSettings.CacheBundleInfoFileName);
 				}
 				return _cachedInfoFilePath;
 			}
diff --git a/Assets/YooAsset/Runtime/PackageSystem/PackageManifest.cs b/Assets/YooAsset/Runtime/PackageSystem/PackageManifest.cs
index 78bc911..a2d4948 100644
--- a/Assets/YooAsset/Runtime/PackageSystem/PackageManifest.cs
+++ b/Assets/YooAsset/Runtime/PackageSystem/PackageManifest.cs
@@ -114,7 +114,7 @@ namespace YooAsset
 					// 添加无后缀名路径的映射
 					if (Path.HasExtension(location))
 					{
-						string locationWithoutExtension = StringUtility.RemoveExtension(location);
+						string locationWithoutExtension = PathUtility.RemoveExtension(location);
 						if (AssetPathMapping.ContainsKey(locationWithoutExtension))
 							YooLogger.Warning($"AssetPath have existed : {locationWithoutExtension}");
 						else
diff --git a/Assets/YooAsset/Runtime/Utility/YooUtility.cs b/Assets/YooAsset/Runtime/Utility/YooUtility.cs
index ddde6dd..f1dba37 100644
--- a/Assets/YooAsset/Runtime/Utility/YooUtility.cs
+++ b/Assets/YooAsset/Runtime/Utility/YooUtility.cs
@@ -7,6 +7,60 @@ using System.Security.Cryptography;
 
 namespace YooAsset
 {
+	/// <summary>
+	/// 路径工具类
+	/// </summary>
+	internal static class PathUtility
+	{
+		/// <summary>
+		/// 路径归一化
+		/// 注意：替换为Linux路径格式
+		/// </summary>
+		public static string RegularPath(string path)
+		{
+			return path.Replace('\\', '/').Replace("\\", "/");
+		}
+		
+		/// <summary>
+		/// 移除路径里的后缀名
+		/// </summary>
+		public static string RemoveExtension(string str)
+		{
+			if (string.IsNullOrEmpty(str))
+				return str;
+
+			int index = str.LastIndexOf(".");
+			if (index == -1)
+				return str;
+			else
+				return str.Remove(index); //"assets/config/test.unity3d" --> "assets/config/test"
+		}
+
+		/// <summary>
+		/// 合并路径
+		/// </summary>
+		public static string Combine(string path1, string path2)
+		{		
+			return StringUtility.Format("{0}/{1}", path1, path2);
+		}
+
+		/// <summary>
+		/// 合并路径
+		/// </summary>
+		public static string Combine(string path1, string path2, string path3)
+		{
+			return StringUtility.Format("{0}/{1}/{2}", path1, path2, path3);
+		}
+
+		/// <summary>
+		/// 合并路径
+		/// </summary>
+		public static string Combine(string path1, string path2, string path3, string path4)
+		{
+			return StringUtility.Format("{0}/{1}/{2}/{3}", path1, path2, path3, path4);
+		}
+	}
+
 	/// <summary>
 	/// 字符串工具类
 	/// </summary>
@@ -54,30 +108,6 @@ namespace YooAsset
 			_cacheBuilder.AppendFormat(format, args);
 			return _cacheBuilder.ToString();
 		}
-
-		public static string RemoveFirstChar(string str)
-		{
-			if (string.IsNullOrEmpty(str))
-				return str;
-			return str.Substring(1);
-		}
-		public static string RemoveLastChar(string str)
-		{
-			if (string.IsNullOrEmpty(str))
-				return str;
-			return str.Substring(0, str.Length - 1);
-		}
-		public static string RemoveExtension(string str)
-		{
-			if (string.IsNullOrEmpty(str))
-				return str;
-
-			int index = str.LastIndexOf(".");
-			if (index == -1)
-				return str;
-			else
-				return str.Remove(index); //"assets/config/test.unity3d" --> "assets/config/test"
-		}
 	}
 
 	/// <summary>