The mechanism comprises a cam, a push rod slider and a glide path. The utility model has simple structure. Compared with the drilling pump whose power end is crank-connecting rod mechanism, the volume and weight are greatly reduced. The number of wearing parts is correspondingly reduced, thereby facilitating handling, prolonging the service life of the drilling pump, facilitating multi-cylinder design, and reducing the non-uniformity of displacement and pressure fluctuation when the pump works. The utility model can be used in oil and gas well engineering and other fields using reciprocating pumps.