The mechanical shot peening technology is applied to study the surface strengthening of tungsten plasma facing materials for fusion device. The strengthening effect of tungsten after shot peening was discussed in detail, which included micro morphology, grain refinement, surface roughness, surface hardness and surface residual compressive stress. And the shot peening process parameters were also optimized. The results indicate that it is the optimum shot peening parameters for the brittle and hard tungsten that air pressure of 0.3 MPa, ceramic pellet with the diameter of 0.4 mm and 100 mm pellet distance, which induces the performance enhancement of tungsten plasma facing material. The surface grain refinement phenomenon is obvious. The surface hardness increasement of about 53.5% is obtained, and the residual compressive stress is increased by 8.3 times. And the influence of shot peening technology on surface roughness is not obvious. The maximum roughness is about 1.5μm.