Novel check valve

The utility model provides a novel check valve which comprises a valve rod internally provided with a hollow channel, an end head arranged at the end part of the valve rod, an expansion sleeve and a top sleeve which are sleeved on the valve rod, a ball arranged in the valve rod and a spring used for being contacted with the ball, the expansion sleeve is arranged between the end head and the top sleeve, the top sleeve is connected with the valve rod through a shaft sleeve, and the spring is arranged in the valve rod. The valve rod is connected with an external pipeline through threads and used for pushing the ejector sleeve, inverted teeth are arranged on the inner side face of the ejector sleeve, protrude towards the axis of the ejector sleeve and are used for preventing the ejector sleeve from being clamped on the threads on the outer side face of the valve rod when the ejector sleeve retreats, and an inclined face B and an inclined face C are arranged on the inner sides of the two ends of the expansion slee