According to the working condition of high temperature oxidation and sulphidation corrosion of the ZG35Cr24Ni7SiN heat-resisting stainless steel used for reducing retort in magnesium refining, and the practical situation which the weld metal between the body and cover of reducing retort must possess resisting high temperature oxidation and corrosion, a kind of RM-1 type coated electrode for reducing retorts in magnesium refining with special alloying system and excellent usability has been developed. The RM-1 coated electrode is made of H0Cr21Ni10 wire core and is alloyed chromium and nickel simultaneously through coating material and wire core and some rare-earth oxides are added in coating material. The electrode has been verified to be satisfied the operation requirements of practical production.