Door latch self-locking device

The utility model relates to a door latch self-locking device, which comprises a door plate and a latch plate. The latch plate is restrained on the back surface of the door plate and can slide relative to the door plate, a latch head is connected to the front end of the latch plate, a vertical wall upwards extending is further disposed on the back surface of the door plate and provided with a guide hole, and the latch head can penetrate outwards via the guide hole. The door latch self-locking device is characterized by further comprising a fastening plate, a support, a top plate and a tension spring, wherein the fastening plate is fixed on one side of the latch plate, the support is fixed on the back surface of the vertical wall, the middle of the top plate is rotationally connected onto the support and can rotate in a direction perpendicular to the vertical wall, the vertical wall is provided with a strip-shaped hole, the front end of the top plate can penetrate out of the strip-shaped hole, the length direction of the strip-shaped hole is perpendicular to the door plate, the rear end of the top plate is provided with a baffle plate extending towards the direction of the latch plate, when the latch head retracts inwards, the baffle plate can limit the front of the fastening plate, and the tension spring is acted onto the top plate so that the baffle plate at the rear end of the top plate keeps a state of limiting the front of the fastening plate. The door latch self-locking device can ensure that the latch head is still concealed when a door is opened, and ensure that the latch head can extend out to be fittingly locked with a door frame when the door is closed.