The utility model relates to an energy-saving hydraulic mixture device in oil extraction well stations, which is composed of a hydraulic control assembly 1, an electric control assembly 2, a change-over valve 3, an accumulator 4, a hydraulic cylinder 5, a discharge line 6, a water injection line 7 and a foundation 8. The utility model is novel in design and reliable in work, which can satisfy flow-regulating requirements of low-pressure water injection wells and meanwhile satisfy output requirements of the fluid in oil wells. The utility model can replace the crude oil output pump of the original process to achieve the good effects of saving energy, decreasing consumption, reducing maintenance workload and expenses, which is easy to extend application.