Aiming at the problem of complicated faults and few fault samples of the axial piston pump, firstly, a simulation model of the axial piston pump was established based on AMEsim. By changing the relevant parameters of the simulation model, three types of faults are simulated: abrasive wear of the rotor-piston friction pair, abrasive wear of the rotor-oil separator friction pair, and slipper edge collapse, and the law of the oil volume changing with the failure is analyzed. Then, an axial piston pump fault injection test system was built to test two types of faults: abrasive wear of the rotor-piston friction pair and sliding shoe collapse. The results show that the test results are similar to the simulation results, and the combined analysis can provide a reference for the tracing of the failure mechanism of the piston pump.