In view of energy-saving aimed reconstruction of the hydraulic system of ZL50 loader, a mechanical model is established, and relevant combined simulation is carried out. The mechanical model of ZL50 loader is built in ADAMS and constrain pairs are added onto the model, meanwhile, the reconstructed hydraulic system of ZL50 loader is formed in AMEsim. Finally, the combined simulation of the hydraulic and mechanical system is realized, thus the actual operation status of ZL50 loader is accurately simulated.