Taking a certain crane cab as the research object, firstly, according to the geometric model of the cab body-in-white, the finite element simulation model is established, and the finite element simulation modal calculation is carried out, and the first six natural frequencies and mode shapes of the cab simulation calculation are analyzed. The test natural frequency and modal shape of the body-in-white are obtained through the LMS data acquisition system, and the modal theory is used to analyze the modal correlation between the calculated mode and the experimental mode. Correctness is checked and verified. The results show that the finite element simulation model has high accuracy and can simulate the overall performance of the actual structure, which can provide real data for later product optimization.