First, go to Liucha Road, go up to Dashu Hanging Yard from the middle of the bottom, then the last one is to go to Sky City (every hour 15 minutes, there is a boat at 45 minutes), wait a few minutes (six or seven minutes), then turn right to see the flight attendant, tell him to go to Shenmu Village, then turn right to see the boat, and wait until the boat comes.
Another convenient way is to open the map with W, and then press ESC to see the "steeple forest" (actually Shenmu). When you find Shenmu Village, double-click and use the mobile ticket to get there. When you come back, just open the map and go back to Treasure Island. This function is free 5 times a month. It is recommended to use it when crossing the mainland.