Hydraulic booster pump

The invention relates to a hydraulic booster pump which comprises a cylinder body, a piston, a reversing valve element, a left pump head, a right pump head, a left plunger, a right plunger, a liquid inlet valve set, a liquid drainage valve set, a pressure relief assembly and a bottom plate gland. The diameter of the left plunger is equal to that of the right plunger, the left pump head is installed at the left end of the cylinder body, the right pump head is installed at the right end of the cylinder body, and the left pump head and the right pump head are connected and fastened with the cylinder body through bolts respectively. The diameter of an inner hole of the cylinder body is D1, D2 and D3 in sequence from left to right, D1 is equal to D3, D2 is smaller than D3, an oil inlet and an oil return port are formed in the cylinder body, the oil inlet is located at the right end of the inner hole of D2, and the oil return port is located at the left end of the inner hole of D2; an oil control channel and a pres