The invention discloses a power balance oil extractor. The power balance oil extractor mainly solves the problem that the existing oil extractor has bad movement performance, big loading fluctuation, high energy consumption and bigger adjusting parameter and adjusting balance strength. The power balance oil extractor is characterized in that a reducer drives an oil pumping crank by a main output shaft and drives a power balance heavy crank by an auxiliary output shaft; the rotating speed of the auxiliary output shaft is two times of the rotating speed of the main output shaft; the power balance heavy crank at the dead center position above the oil pumping crank lags behind 90 degrees with respect to the oil pumping crank; the power balance heavy crank at the dead center position under theoil pumping crank advances 90 degrees with respect to the oil pumping crank; a flexible oil pumping rope bypasses an oil pumping chain wheel at the upper end of a well-head bracket and a crank chain wheel on the crank in sequence, and then is fixed on a gemel seat which is fixed on a connecting rod; and both ends of the connecting rod are respectively fixed on a machine frame and the well-head bracket. The oil extractor stably operates, has simple structure, convenient parameter and balance adjustment, stable electromotor power, reducer torsion and loading fluctuation.