It works!

src/main/java/fr/xephi/authme/AuthMe.java

@@ -22,7 +22,7 @@ import fr.xephi.authme.listener.PlayerListener;
 import fr.xephi.authme.listener.PlayerListener111;
 import fr.xephi.authme.listener.PlayerListener19;
 import fr.xephi.authme.listener.PlayerListener19Spigot;
-import fr.xephi.authme.listener.PlayerQuitListener;
+import fr.xephi.authme.listener.DoubleLoginFixListener;
 import fr.xephi.authme.listener.GuiCaptchaHandler;
 import fr.xephi.authme.listener.ServerListener;
 import fr.xephi.authme.mail.EmailService;
@@ -85,7 +85,7 @@ public class AuthMe extends JavaPlugin {
     private BukkitService bukkitService;
     private Injector injector;
     private BackupService backupService;
-    private ConsoleLogger logger;
+    public static ConsoleLogger logger;
     /**
      * Constructor.
      */
@@ -207,7 +207,7 @@ public class AuthMe extends JavaPlugin {
         // 注册玩家退出事件监听
         if (settings.getProperty(SecuritySettings.ANTI_GHOST_PLAYERS) || settings.getProperty(SecuritySettings.SMART_ASYNC_TELEPORT)/* || settings.getProperty(SecuritySettings.GUI_CAPTCHA)*/) {
             if (settings.getProperty(SecuritySettings.ANTI_GHOST_PLAYERS)) {
-                getServer().getPluginManager().registerEvents(new PlayerQuitListener((Plugin) this), this);
+                getServer().getPluginManager().registerEvents(new DoubleLoginFixListener((Plugin) this), this);
             }
             if (settings.getProperty(SecuritySettings.GUI_CAPTCHA) && getServer().getPluginManager().isPluginEnabled("ProtocolLib")) {
                 getServer().getPluginManager().registerEvents(new GuiCaptchaHandler((Plugin) this), this);

src/main/java/fr/xephi/authme/listener/DoubleLoginFixListener.java

@@ -0,0 +1,50 @@
+package fr.xephi.authme.listener;
+//Prevent Ghost Players
+
+import fr.xephi.authme.AuthMe;
+import org.bukkit.Bukkit;
+import org.bukkit.entity.Player;
+import org.bukkit.event.EventHandler;
+import org.bukkit.event.Listener;
+import org.bukkit.event.player.PlayerJoinEvent;
+import org.bukkit.plugin.Plugin;
+
+import java.util.Collection;
+import java.util.HashSet;
+
+public class DoubleLoginFixListener implements Listener {
+    private final Plugin plugin;
+
+
+
+    public DoubleLoginFixListener(Plugin plugin) {
+        this.plugin = plugin;
+
+    }
+    @EventHandler
+    public void onPlayerJoin(PlayerJoinEvent event) {
+        Collection<? extends Player> PlayerList = Bukkit.getServer().getOnlinePlayers();
+        HashSet<String> PlayerSet = new HashSet<String>();
+        for (Player ep : PlayerList) {
+            if (PlayerSet.contains(ep.getName().toLowerCase())) {
+                ep.kickPlayer("You have been disconnected due to doubled login.");
+                break;
+            }
+            PlayerSet.add(ep.getName().toLowerCase());
+        }
+    }
+}
+//    @EventHandler
+//    public void onPlayerQuit(PlayerQuitEvent event) {
+//        Player player = event.getPlayer();
+//        String LastAddr = Objects.requireNonNull(player.getAddress()).getAddress().getHostAddress();
+//        Bukkit.getScheduler().runTaskLater(plugin, new Runnable() {
+//            @Override
+//            public void run() {
+//                if (player.isOnline()) {
+//                    player.kickPlayer("You have been disconnected.");
+//                }
+//            }
+//        }, 20L); // 20 ticks = 1 second
+//    }
+//}

src/main/java/fr/xephi/authme/listener/GuiCaptchaHandler.java

@@ -1,14 +1,11 @@
 package fr.xephi.authme.listener;
-
 import com.comphenix.protocol.PacketType;
 import com.comphenix.protocol.ProtocolLibrary;
 import com.comphenix.protocol.events.ListenerPriority;
 import com.comphenix.protocol.events.PacketAdapter;
 import com.comphenix.protocol.events.PacketEvent;
-
 import fr.xephi.authme.AuthMe;
 import fr.xephi.authme.api.v3.AuthMeApi;
-
 import fr.xephi.authme.settings.properties.HooksSettings;
 import fr.xephi.authme.settings.properties.RestrictionSettings;
 import fr.xephi.authme.settings.properties.SecuritySettings;

src/main/java/fr/xephi/authme/listener/PlayerQuitListener.java

@@ -1,31 +0,0 @@
-package fr.xephi.authme.listener;
-//Prevent Ghost Players
-
-import org.bukkit.Bukkit;
-import org.bukkit.entity.Player;
-import org.bukkit.event.EventHandler;
-import org.bukkit.event.Listener;
-import org.bukkit.event.player.PlayerQuitEvent;
-import org.bukkit.plugin.Plugin;
-
-import java.util.Objects;
-
-public class PlayerQuitListener implements Listener {
-    private final Plugin plugin;
-    public PlayerQuitListener(Plugin plugin) {
-        this.plugin = plugin;
-    }
-    @EventHandler
-    public void onPlayerQuit(PlayerQuitEvent event) {
-        Player player = event.getPlayer();
-        String LastAddr = Objects.requireNonNull(player.getAddress()).getAddress().getHostAddress();
-        Bukkit.getScheduler().runTaskLater(plugin, new Runnable() {
-            @Override
-            public void run() {
-                if (player.isOnline()) {
-                    player.kickPlayer("You have been disconnected.");
-                }
-            }
-        }, 20L); // 20 ticks = 1 second
-    }
-}