Self-sealing rod type oil well pump

The utility model discloses a self-sealing rod type oil well pump, which relates to the technical field of rod type oil well pumps, and comprises a pump seat and a pump body, the pump body comprises a pump cylinder and a plunger assembly, the plunger assembly comprises a valve rod joint, a valve rod and a plunger which are fixedly connected up and down, and the plunger assembly is arranged in the pump cylinder in an up-down sliding mode. The pump cylinder is detachably inserted into the pump base in a sealed mode through a locking connector arranged at the lower end of the pump cylinder, the upper end of the pump cylinder is connected with an upper self-sealing assembly used for sealing the pump cylinder and an oil pipe annulus, the upper self-sealing assembly comprises a rubber cylinder and a self-locking piece used for locking the rubber cylinder in an expansion state, and the rubber cylinder is arranged on the self-locking piece in a sleeving mode. The self-locking piece is arranged on the outer side of th