The invention discloses an electromechanical commutator for an oil pumping unit, which comprises a front-row planet gear system and a rear-row planet gear system, wherein the two planet gear systems share one planet carrier; a rear brake disc is fixed on the planet carrier; the rear brake disc and a normally-closed rear electromagnetic disk brake form a brake device; a front brake disc is fixed on a front-row center wheel; the front brake disc and a normally-closed front electromagnetic disk brake form another brake device; an input shaft is fixedly connected with a front-row inner gear ring and a rear-row center wheel; the front-row center wheel and the planet carrier are idled with the input shaft; a rear-row inner gear ring is fixedly connected with an output shaft; the front-row planet gear is simultaneously meshed with the front-row center wheel and the front-row inner gear ring; and the rear-row planet gear is simultaneously meshed with the rear-row center wheel and the rear-row inner gear ring. According to the electromechanical commutator for the oil pumping unit, a series of problems brought by the fact that a reciprocating rotary oil pumping unit directly commutates by an electromotor can be solved, and therefore, the electromechanical commutator for the oil pumping unit has an important practical value.