Abstract: The crack of SiC_p/Cu composite weld restored by electro-spark overlaying was processed by Nd: glass laser, and effects of laser shock processing on the electro-spark overlaying weld crack were analyzed.Surface welding residual stress distribution alone the transverse direction of the weld was investigated by X-ray diffraction techniques, the tensile strength of the weld was investigated by strength test, and the micro-hardness distribution of the weld surface was measured with a micro-hardness tester.The results show that when laser power is 35 J and laser spot diameter is 5 mm, the laser shock processing can reduce the welding residual stresses, which even change from the tensile stress into compressive stress, and improve the tensile strength and the hardness of SiC_p/Cu composite weld restored by electro-spark overlaying.