Diaphragm type check valve

The utility model discloses a diaphragm type check valve, which belongs to the technical field of check valves and comprises a main valve body, a matched auxiliary valve body is arranged on one side of the main valve body, the main valve body and the auxiliary valve body are fixedly connected in a fastening mode, an outer convex circle part is arranged on the adjacent end sides of the main valve body and the auxiliary valve body, and the outer convex circle part is arranged on the outer convex circle part. Grooves are formed in the two outer convex circle parts of the main valve body and the two outer convex circle parts of the auxiliary valve body correspondingly, a valve seat and a rubber diaphragm of an annular structure are clamped and fixed between the grooves, an inner ring of the rubber diaphragm is connected with an abutting plate, a plurality of liquid passing pipe openings are formed in the abutting plate in a penetrating mode, and a center column rotationally connected with the valve seat is arrang