Stainless steel pickling inhibitor

The invention belongs to the technical field of surface treatment and in particular relates to a stainless steel pickling inhibitor which has a purpose of removing stainless steel scales with different brands. The stainless steel pickling inhibitor contains a compound with a '=C-NH2-' structure, an alkyne compound, copper ions and polyethylene glycol, wherein 0.12-2.3 g compound with the '=C-NH2-' structure is added to each liter of tank liquor; the usage of the alkyne compound in the plating liquid is 0.1-0.8 g in each liter of tank liquor; the usage of the copper ions in the plating liquid is 0.5-2 g in each liter of tank liquor; and the usage of the polyethylene glycol in the plating liquid is 0.2-0.6 g in each liter of tank liquor. Through adding the chemical substances capable of having adsorption effect on the surface of the stainless steel substrate and copper salts capable of generating a replacement protective copper layer on the surface of the active material, the surface of the exposed fresh stainl