Abstract: In order to evaluate the performance of the working device of the DL300 bulldozer and loader, a typical working condition stress analysis was conducted based on the analysis of load relationship at the hinge point of the working device. The working device postures at completion of bucket collection and the moment of unloading were determined as the typical postures. The finite element simulation analysis was conducted based on the measured peak load in public literature, and the stress cloud maps corresponding to the measured peak load in two typical postures were obtained. And the corresponding fatigue assessment location for the high stress area was also determined. The research results and conclusions provide a basis for load testing and fatigue analysis of the working device of this type of equipment.