diff --git a/hutool-extra/src/main/java/cn/hutool/extra/ftp/AbstractFtp.java b/hutool-extra/src/main/java/cn/hutool/extra/ftp/AbstractFtp.java
index 052e79de6..ffc5bd1b8 100644
--- a/hutool-extra/src/main/java/cn/hutool/extra/ftp/AbstractFtp.java
+++ b/hutool-extra/src/main/java/cn/hutool/extra/ftp/AbstractFtp.java
@@ -2,6 +2,7 @@ package cn.hutool.extra.ftp;
 
 import cn.hutool.core.collection.CollUtil;
 import cn.hutool.core.io.FileUtil;
+import cn.hutool.core.util.CharUtil;
 import cn.hutool.core.util.CharsetUtil;
 import cn.hutool.core.util.StrUtil;
 
@@ -73,7 +74,12 @@ public abstract class AbstractFtp implements Closeable {
 	 * @since 5.7.5
 	 */
 	public boolean isDir(String dir) {
-		return cd(dir);
+		final String workDir = pwd();
+		try {
+			return cd(dir);
+		} finally {
+			cd(workDir);
+		}
 	}
 
 	/**
@@ -91,8 +97,22 @@ public abstract class AbstractFtp implements Closeable {
 	 * @return 是否存在
 	 */
 	public boolean exist(String path) {
+		if (StrUtil.isBlank(path)) {
+			return false;
+		}
+		// 目录验证
+		if (isDir(path)) {
+			return true;
+		}
+		if (CharUtil.isFileSeparator(path.charAt(path.length() - 1))) {
+			return false;
+		}
 		final String fileName = FileUtil.getName(path);
-		final String dir = StrUtil.removeSuffix(path, fileName);
+		if (".".equals(fileName) || "..".equals(fileName)) {
+			return false;
+		}
+		// 文件验证
+		final String dir = StrUtil.emptyToDefault(StrUtil.removeSuffix(path, fileName), ".");
 		final List<String> names;
 		try {
 			names = ls(dir);
diff --git a/hutool-extra/src/test/java/cn/hutool/extra/ftp/FtpTest.java b/hutool-extra/src/test/java/cn/hutool/extra/ftp/FtpTest.java
index 2b8cbc425..6dc04d292 100644
--- a/hutool-extra/src/test/java/cn/hutool/extra/ftp/FtpTest.java
+++ b/hutool-extra/src/test/java/cn/hutool/extra/ftp/FtpTest.java
@@ -90,4 +90,63 @@ public class FtpTest {
 					FileUtil.file("d:/test/download/" + name));
 		}
 	}
+
+	@Test
+	@Ignore
+	public void isDirTest() throws Exception {
+		try (Ftp ftp = new Ftp("127.0.0.1", 21)) {
+			Console.log(ftp.pwd());
+			ftp.isDir("/test");
+			Console.log(ftp.pwd());
+		}
+	}
+
+	@Test
+	@Ignore
+	public void existSftpTest() throws Exception {
+		try (Sftp ftp = new Sftp("127.0.0.1", 22, "test", "test")) {
+			Console.log(ftp.pwd());
+			Console.log(ftp.exist(null));
+			Console.log(ftp.exist(""));
+			Console.log(ftp.exist("."));
+			Console.log(ftp.exist(".."));
+			Console.log(ftp.exist("/"));
+			Console.log(ftp.exist("a"));
+			Console.log(ftp.exist("/home/test"));
+			Console.log(ftp.exist("/home/test/"));
+			Console.log(ftp.exist("/home/test//////"));
+			Console.log(ftp.exist("/home/test/file1"));
+			Console.log(ftp.exist("/home/test/file1/"));
+			Console.log(ftp.exist("///////////"));
+			Console.log(ftp.exist("./"));
+			Console.log(ftp.exist("./file1"));
+			Console.log(ftp.pwd());
+		}
+	}
+
+	@Test
+	@Ignore
+	public void existFtpTest() throws Exception {
+		try (Ftp ftp = new Ftp("127.0.0.1", 21)) {
+			Console.log(ftp.pwd());
+			Console.log(ftp.exist(null));
+			Console.log(ftp.exist(""));
+			Console.log(ftp.exist("."));
+			Console.log(ftp.exist(".."));
+			Console.log(ftp.exist("/"));
+			Console.log(ftp.exist("a"));
+			Console.log(ftp.exist("/test"));
+			Console.log(ftp.exist("/test/"));
+			Console.log(ftp.exist("/test//////"));
+			Console.log(ftp.exist("/test/.."));
+			Console.log(ftp.exist("/test/."));
+			Console.log(ftp.exist("/file1"));
+			Console.log(ftp.exist("/file1/"));
+			Console.log(ftp.exist("///////////"));
+			Console.log(ftp.exist("./"));
+			Console.log(ftp.exist("./file1"));
+			Console.log(ftp.exist("./2/3/4/.."));
+			Console.log(ftp.pwd());
+		}
+	}
 }