The invention provides a welding method aiming at the butt welding of small caliber resistances. The method is applicable to the welding of small caliber steel pipes, wire rods and rings, and also applicable to the contact butt welding of small caliber nonferrous metals such as aluminium and magnesium wire rods and pipe products, belonging to the welding technical field. As stainless steel is slow in heat dissipation, the invention proposes a welding technique with intermittent heating and continuous and uneven heat dissipation. The high temperature plastic zone in the welding temperature field obtained by the process is narrow and can be less affected by the contact resistances; the welding shrinkage can be controlled accurately by the process; the welding line moulding has a beautiful appearance; the strength and the through-hole both meet the requirements, thus greatly improving the qualification rate of products.