With 3D modeling software SolidWorks, 3D model of portable core drill power head was built, which was introduced into the finite element analysis software ANSYS Workbench to obtain finite element model. Based on the finite element analysis method, the dynamic characteristics and other mechanical properties of the key components in the power h西南地区典型重大突发地质灾害调查（编号：12120113096700）ead were analyzed respectively. The analysis on the strain and deformation of gears during drilling process proved that the gears met rigidity, strength and other mechanical properties; and the contact conditions of gears contact area was also analyzed. The simulation was made on drill pipe hoisting and lowering, pressure drilling and decompressed drilling to analyze the force and deformation of the spindle to provide basis for the spindle design. The analysis was made on the strain and deformation of gear box in the drill pipe hoisting and lowering process to prove good rigidity and strength; according to the modal analysis on the box, the natural frequency of the box is obtained and the dynamic performance of the box is verified.