By analyzing the hydraulic system circuit diagram of the all terrain crane’〖KG-*2〗s two axles hydropneumatic suspension(HPS), 7 DOF mathematical model of the two axles HPS group was established. The main differences of independent type and parallel type two axles HPS model were also studied, and their simulation models were set up based on AMESim software. The maximum pressure, tire dynamic load, and vertical acceleration about the independent type and parallel type two axles HPS model were comparatively analyzed. The conclusion is that the performance index of the parallel type two axles HPS is superior to that of the independent two axles HPS.