Novel energy-efficient oil pumping unit decelerator

A novel energy-efficient oil pumping unit decelerator belongs to the oil production mechanical equipment unit field. The decelerator comprises a decelerator body (1) and a fine adjustment tail counterweight balancing unit (2). the fine adjustment tail counterweight balancing unit (2) is disposed on the walking beam tail end of the decelerator body (1). Because of the fine adjustment tail counterweight balancing unit mounted on the walking beam tail end, the decelerator of the utility model increases the input power and the input power stability of the oil pumping unit, can adjust the balance of the input power effectively, and reduce the influence of shock loading to the input power; at the same time, prolongs the service lives of all rotation components, reduces maintenance cost effectively, and reduces the labor intensity of oil production workers.