In order to provide basis for vibration and noise reduction of loader gearbox, the vibration analysis of gearbox was carried out by combining centralized parameters and finite element method. Considering the excitation of hydraulic torque converter and gear system internal excitation factors, a loader gearbox transmission system of bend-torsion coupling dynamic model was established, the dynamic reaction force of each bearing was solved. The casing finite element model was established for modal analysis, taking the bearing dynamic reaction force as the excitation, the modal harmonic response analysis was conducted on the basis of enclosure. The vibration response of the box under the excitation was obtained, the vibration measurement points on the surface of the box were selected, the vibration acceleration of the measurement points was analyzed, the vibration peak value and corresponding vibration mode were found and analyzed, and finally the gearbox vibration test was conducted to verify the correctness of the simulation. The results show that the excitation of the transmission system is mainly concentrated at the input and output parallel shaft gears, the vibration peak frequency of the transmission system and the box body is close to the meshing frequency of the gear, and the larger vibration of the box body is located at the bottom of the box body. Compared with the simulation, the peak frequency in the test is similar to that in the simulation, and the root mean square error of the vibration acceleration obtained by the simulation is less than 20%, which verifies the correctness of the simulation.