Aimed at the defects of large energy consumption, short stroke, poor athletic performance of the beam pumping unit, and corresponding poor reliability faults in the absence of beam pumping unit of motor commutator and chain commutator, a design program of the new mechanical commutation long stroke pumping unit was proposed. Commutation reducer was composed of two sets of differential, which was used to achieve purely mechanical commutation, and faults existed in motor commutator and chain commutator were avoided. At one time, the performance of pumping unit is analyzed, which achieves the goal of energy conservation and consumption reduction.