Abstract: In this paper, the lightweight design of the cargo compartment of a heavy truck dump truck is systematically studied aiming to improve the transportation efficiency and reduce the energy consumption. Firstly, three-dimensional modeling is carried out by Solid works, and static and modal analyses are conducted on the cargo compartment of a certain type of heavy truck dump truck by using ANSYS Workbench. Secondly, the lightweight design is carried out under the constraint conditions and the expected design premise of ensuring the safety performance of the dump box. Finally, the simulation analysis shows that the mass reduction ratio of optimizing the number of longitudinal and transverse beams of the cargo compartment of heavy truck dump truck is 6.9%, the mass reduction ratio of optimizing the aluminum alloy material of the cargo compartment is 12.8%, and the mass reduction ratio of optimizing the Q245 steel material of the cargo compartment is 9.8%, which verifies the feasibility and validity of the proposed lightweighting scheme. This study not only helps to promote the practical design of the lightweight of the dump truck, but also provides a systematic and scientific research method.