The invention discloses a pumping unit with two-time stroke-doubling balancing, comprising a support, a rotary drum, a sucker rod, a sucker rope, a motor and a speed reducer, wherein the support, the motor and the speed reducer are located on a base and the rotary drum is arranged on the support. The pumping unit is characterized in that the motor is connected with the speed reducer; an output shaft of the speed reducer is connected with a balance transmission shaft through a coupler; the balance transmission shaft is connected with a large balance lock; the balance transmission shaft is further connected with a driven shaft through a transmission mechanism; and a small balance block is arranged on the driven shaft. The output power of the motor of the pumping unit with the two-time stroke-doubling balancing is primarily balanced by the large balance block, and then transferred to the small balance block through a transmission chain for secondary balance; as a result, the power output by the motor in upper and lower strokes is effectively balanced, the service life of the motor and the service life of the pumping unit are prolonged, the uniformity of the rotating speed of a crank is ensured, and normal operations of the sucker rod and an oil well pump are guaranteed.