In order to study the working characteristics of mining face-shovel hydraulic excavator with bucket capacity of 15m3 and machine weight of 260t, which is currently the largest tonnage of hydraulic excavator, co-simulation method of the dynamics of mechanical systems and hydraulic systems to the small excavator was authenticated. Then, by comparing the results of test and co-simulation, it was confirmed that co-simulation method could accurately simulate the practical working environment of excavator. On the base of before-mentioned research, mechanical devices and hydraulic systems of mining hydraulic excavator which bucket capacity is 15m3 were carried on with the help of ADAMS and AMESim software. Through simulation the rotation inertias of various parts of working mechanism to its rotation axis during working process were calculated. The displacement curves, velocity curves, force curves of each hydraulic cylinder and the excavating trajectory of bucket tooth crest could be obtained through co-simulation.