Water well anti-relief valve

The utility model relates to a water well anti-relief valve applied in a water injection well at an oil field, consisting of a pressure rod, an upper joint, a seal ring, a valve seat, a valve ball, a spring seat, a spring and a lower joint. The water well anti-relief valve is characterized in that: the lower part of the upper joint is connected with the upper part of the lower joint, the seal ring is sleeved on the thread at the lower part of the upper joint and is inside the upper part of the lower joint, the seal ring is to seal the joint position of the upper joint and the lower joint; the valve seat is arranged below the thread at the upper part of the lower joint and is also below the upper joint, the valve ball seat is arranged below the valve seat and above the spring seat; the spring seat is arranged on the spring which is arranged inside the lower part of the lower joint; the pressure rod is positioned inside the upper joint, and the lower part of the pressure rod is contacted with the valve ball. In the test and preparation, no overflow is necessary, the water injected into the well can not spray back to the ground, the ground pressure is not reduced and the environment is not polluted, therefore, the environmental pollution improvement expense is not needed; after the injection, the test and preparation operation can be carried out immediately, the water injection time is increased as well as the water injection rate.