The utility model discloses a quick automatic hasp, on the fixed bulkhead externally of this hasp, what the bulkhead was vertical is connected with a platform, the through -hole has been seted up on the platform, be equipped with the rotatable flip who opens or close on the through -hole, this hasp includes that the hasp puts up and the hasp floodgate, the one end of hasp frame with the upper portion of bulkhead is connected, its other end with hasp floodgate hinged joint, wherein, the outer tip of hasp frame still is equipped with a stopper, works as when the hasp floodgate does not receive external force, the lateral surface of hasp floodgate with stopper looks butt, just the bottom distance of hasp floodgate the vertical height of through -hole is less than flip's radius of gyration. The utility model discloses can reach automatic effect of pinning flip, it is simple structure not only, and it is easy to make, convenient to use in addition, and the security is high.