Axial-flow type check valve with good sealing performance

The utility model belongs to the technical field of check valves, particularly relates to an axial-flow type check valve with good sealing performance, and aims to solve the problems that a long thread valve rod of a conventional check valve is lack of a positioning structure, so that the sealing stability of a flashboard cannot be guaranteed, and the possibility of leakage exists when multiple parts of the check valve are assembled, the axial-flow type check valve comprises a pipe body, the outer side of the pipe body is communicated with a valve cover, the top of the valve cover is fixedly provided with a second connecting pipe through a plurality of screws, the top of the second connecting pipe is fixedly communicated with a long pipe, the top of the long pipe is fixedly provided with a fixed cylinder, a long thread valve rod is rotatably installed in the fixed cylinder, and a gate plate is rotatably installed in the pipe body. The check valve is reasonable in structural design, rotation of the hand ring i