The reciprocating double-acting oil pump, including a small pump barrel, a small plunger, a large pump barrel, a large plunger, a fixed valve, a traveling valve and an upper oil outlet valve cover, is characterized in that:

The lower end of the outer tube is connected and fixed with the upper end of the three-buckle joint through the first coupling, the lower end of the small pump cylinder is fixed with the inner wall of the three-buckle upper mouth, the lower end of the three-buckle joint is fixed with the upper end of the upper short tube, and the lower end of the upper short tube passes through the second The coupling is connected and fixed with the upper end of the large pump barrel, the lower end of the large pump barrel is connected and fixed with the upper end of the lower short pipe through the third coupling, the lower end of the lower short pipe is connected and fixed with the fixed valve through the lower coupling, and the lower end of the small plunger. The two-way core assembly is connected and fixed with the upper end of the large plunger, the lower end of the large plunger is fixed with a swimming valve, the side wall of the large pump cylinder is provided with an oil inlet, and the two-way core assembly is located in the upper short pipe. The cavity structure of the utility model is simple and reliable, the working performance is more stable, and the oil extraction efficiency is effectively improved.