The integrated piston-plunger pump integrated the piston engine and plunger pump technology as a whole. The hydrodynamic power was produced by the piston reciprocating rectilinear motion. The test showed that output pressure of the total working conditions of the pump was improved by 15.21% to 76.61%, output flow reduced by 0.69% to 2.13% and output power increased by 13.63% to 74.75%, compared with piston engine driving piston pump system. The rated output index was achieved under the 80% throttle, the output pressure of 1.15MPa, the output flow of 4.8m3/h and the corresponding rotate speed of the pump about 1900r/min. The integrated piston-plunger pump had correct working principle and operates normally, achieving the desired design function.