The invention relates to a power end of a plunger pump. The power end comprises a body, a crankshaft and N groups of transmission components, wherein the crankshaft is arranged in the body, and the transmission components are driven to reciprocate radially by the crankshaft. The N groups of transmission components are connected with N plungers at a hydraulic end respectively, wherein N refers to a natural number. Two ends of the crankshaft are connected with the body through bearings respectively. The power end is characterized in that when N is larger than or equal to 2, fulcrum connection structures in quantity larger than or equal to 3 and smaller than or equal to N+1 are arranged between the crankshaft and the body, and the fulcrum connection structures include bearing connection structures between two ends of the crankshaft and the body and bearing connection structures between the crankshaft and the fixing support plates, in quantity larger than or equal to 1 and smaller than or equal to N-1, arranged in the body. Compared with the prior art, the power end has advantages that the service life of a mechanical link part between the body and the crankshaft can be effectively prolonged, and cracking and roughening of a hole end of a slide way of the body can be prevented.