Abstract: The power head of truck-mounted drilling rig was taken as the research object, the functional requirement was proposed and the design scheme was determined under the maximum working load. The 3D digital power head model was established by using three-dimensional modeling software, and the finite element analysis was carried out for key components of power head through CAE software, the distribution law of stress and strain was obtained in the working process. According to the results of numerical simulation, the initial design scheme was optimized. The field application result of the prototype showed that the power head design could meet the function requirement of truck-mounted drilling rig and had a high reliability.