Abstract: Aiming at bulky grains and declination of mechanical properties of K403 nickel-alloy repaired by laser cladding, the laser shock processing(LSP) technology was applied to strengthen the surface of repaired region. The microstructuree was observed through SEM and the mechanical properties were represented by testing microhardness, residual stress and high temperature tensile strength. The results show that the LSP refines crystalline grain of the surface of the specimen. After LSP, the surface hardness of matrix region and cladding zone were improved by 21% and 8% respectively. The hardness affected depth of the LSP was about 0.8 mm. Besides, about 610 MPa and equally distributed residual compressed stress was generated and the affected depth was about 1.2 mm. After thermal retardation, the residual compressed stress was released by about 18%, but high residual compressed stress also existed on surface. The high temperature tensile strength was increased by about 15% after LSP. The problem of mechanical properties decrease of K403 nickel-alloy repaired by laser cladding was solved.