The invention discloses a novel high-performance four-cylinder plunger pump comprising a pump body internally provided with a cross-shaped pump cavity. Piston devices are transversely and longitudinally arranged in the pump cavity and sealed by two layers. The upper end, the lower end, the left end and the right end of the pump body are in sealed connection with pump covers correspondingly, and containing cavities are formed between the pump covers and the pump body correspondingly. The piston devices separate the pump cavity from the four containing cavities, so that it is guaranteed that a transmission piece in the pump can operate under the sealed condition all the time. The piston devices move around to drive liquid in the containing cavities to be imbibed and pressed out, and therefore pressure-applying discharging of the liquid in the four-cylinder plunger pump is completed. The plunger pump of a four-cylinder structure is achieved through two pistons, noise is low, the working pressure is enlarged, the pressurizing efficiency is obviously improved, stability is high, and the displacement is large; through double-layer sealing of the pistons, the sealing effect of the plunger pump is better, and water leakage is avoided; the pump body is internally lubricated, so that the transmission piece in the pump body is not liable to be damaged, the failure rate of the pump body is decreased, and the service life of the plunger pump is greatly prolonged; and the novel high-performance four-cylinder plunger pump has the advantages of simple and firm structure, convenient manufacturing and convenient dismounting and mounting.