Adjustable axial-flow type check valve

The utility model relates to an adjustable axial-flow type check valve which comprises a valve body, wherein a diversion hood is arranged in the valve body; the center position of the division hood is provided with a mounting hole formed along the axis direction of the diversion hood; an adjusting sleeve is inserted in the mounting hole; one end of a valve shaft is fixedly connected with a valve clack arranged in the valve body after penetrating through the adjusting sleeve; the adjusting sleeve is in threaded connection with the valve shaft; one end, which is adjacent to the valve clack, of the adjusting sleeve is arranged in a manner of extending outwards along the radial direction of the adjusting sleeve; the inner wall of the mounting hole is provided with two guide raised lines which are oppositely arranged along the axis direction of the mounting hole; the parts, which correspond to the two guide raised lines, of the outer surface of the adjusting sleeve are provided with two clamping slots matched with the guide raised lines; the outer side of the valve shaft between the adjusting sleeve and the valve clack is sleeved by a spring. According to the adjustable axial-flow type check valve, the compression degree of the spring can be changed by virtue of screwing the valve shaft to enable the adjusting sleeve to move back and forth, so that the valve clack is clung to the sealing surface of a valve base of the valve body under the action of a pretightening force of the spring, and normal automatic closing of the valve is ensured.