Abstract: To address the problems of surface wear, scoring and corrosion failure that easily occur on the piston rod of hydraulic cylinder of underground coal mine drilling rigs under long-term service in harsh environments with high load, strong corrosion and high dust content, this paper conducts a study on the laser cladding remanufacturing process to improve the surface hardness, wear resistance and corrosion resistance of the piston rod and extend its service life. Using 40CrMo piston rod as the substrate, laser cladding technology was adopted to optimize cladding materials, schemes and process parameters, so as to prepare cladding layers with high hardness, high wear resistance and strong corrosion resistance. The key properties of the cladding layers were comprehensively evaluated through hardness test, wear test, neutral salt spray test and performance attenuation test. The results show that the prepared cladding layer has a dense microstructure, high interfacial bonding strength, and no defects such as pores and cracks. All indicators meet the actual working conditions of underground coal mine drilling rigs. A stable and efficient laser cladding remanufacturing process and supporting inspection specifications have been formed. The remanufacturing process can significantly improve the wear and corrosion resistance of the piston rod, effectively extend its service life, and reduce maintenance frequency and operation and maintenance costs.