Abstract: The method of combining experiment and theory was adopted to study application of monolayer strip electrode electroslag surfacing technology on inner wall of hydrogenation equipment shell. Surfacing tests were carried out on 14Cr1MoR(H) and 12Cr2Mo1R(H) materials commonly used in hydrogenation equipment, and microstructure and mechanical properties of specimens were analyzed. The results showed that under welding parameters in the paper, surfacing thickness of specimens reached 5~7 mm, which exceeded domestic general requirement of 4.0~4.5 mm. Ferrite content of surfacing layer in the welded state was both in the range of 5~10 FN when it was measured by magnetic method and WRC-1992 diagram. Chemical composition on the surface and below 3 mm of surfacing layer met the relevant high standards. No incomplete penetration, cracks or other linear defects appeared in the cross section of surfacing layer. There were no untempered martensite and micro-cracks in surfacing layer, heat affected zone and base material. Hardness of surfacing layer, heat affected zone and base material did not exceed 235 HV10. Test results of surfacing met the expected requirements and better monolayer strip electrode electroslag surfacing parameters for inner wall of hydrogenation equipment shell was determined, which provided a technical basis for development of subsequent products and a certain reference for subsequent research of monolayer strip electrode electroslag surfacing.