The fuel solenoid valve is used to control the oil circuit of the fuel system. In the process of product repair,screw back teeth,thread broken buckle and screw thread slipping often appear,which affects the connection strength of the thread. For the material DT4 used for the fuel solenoid valve’s coil block,the method of laser cladding is used to repair the coil block. The welding strength is demonstrated before the repair,and the nondestructive test and performance inspection are conducted after the repair. The result shows that the method of laser cladding can repair the material DT4,the repaired product can meet the strength requirement. Welding directly on the original thread affects the welding quality. The original thread should be removed during repair to avoid cracks and apertures on the joint surface. Reducing laser power can reduce or eliminate the blow holes.