Anti-backflow oil well Christmas tree

The utility model relates to the anti-backflow technology of an oil well head for an oil field and provides an anti-backflow oil well Christmas tree. The anti-backflow oil well Christmas tree solves the problem of crude oil backflow. The anti-backflow oil well Christmas tree is formed by connecting a large four-way pipe, a tee joint, a communication pipe, a production valve, an oil sleeve communication valve, a pressure return valve, a horizontal oil output pipe, a check valve, a valve seat, a valve cover, a ball seat, a steel ball and an oil output hole. The three-way pipe is arranged on the large four-way pipe of the oil well head, the production valve is arranged on the horizontal pipe connected with the tee joint, and the oil sleeve communication valve is arranged on an oil sleeve communication pipe. The horizontal oil output pipe is connected with a vertical pipe, the check valve is fixedly clamped on the vertical pipe, and the pressure return valve is arranged on a pressure return pipe. A valve cover is fixed to the valve seat of the check valve, the ball seat is fixed in the middle of the valve seat, the steel ball is arranged on the ball seat, and an oil output hole is formed in the top face of the valve cover.