According to the technical requirements of the product,the thickness of surfacing layer of ENiCrMo-3 grade nickel-based alloy shall be greater than or equal to 4.5 mm,the chemical compositions of the surfacing layer surface and 3.2 mm below the surfacing layer surface shall meet the ASME specification Ⅱ volume C. SFA-5.11 ENiCrMo-3,and qualified bending performance terms. The single-layer electroslag surfacing with band-electrode,which can increase the thickness of surfacing,is used to instead the double-layer electroslag surfacing with bandelectrode in the conventional procedure. The surfacing tests were carried out under two working conditions,on the flat plate and the inner wall of the cylinder. And the surfacing parameters were explored. The results show that the amount of uphill is parti-cularly important for the appearance of weld in addition to variables related to welding heat input. Comparing the welding parameters between surfacing on the plate and the inner wall of cylinder with internal diameter of 1 620 mm,the applicable welding parameters vary greatly under the two working condi-tions,when the thickness of single layer surfacing is greater than or equal to 4.5 mm,the applicable welding parameters of these two structures differ greatly,and the surfacing parameters of plate are not suitable for the surfacing of the inner wall of the cylinder.