The invention discloses a metal cleaning agent. The metal cleaning agent comprises, by weight, 16 parts to 20 parts of sodium stearate, 3 parts to 10 parts of methoxy fat amide benzene sulfonic acid sodium, 2 parts to 5 parts of triethanolamine oleate, 4 parts to 6 parts of lauryl diethanolamide, 0.1 part to 0.8 part of sodium metaborate, 0.2 part to 0.6 part of benzotriazole, 6 parts to 10 parts of ethyl alcohol, 2 parts to 4 parts of butyl alcohol, 1 part to 5 parts of silicone oil, 0.3 part to 0.7 part of polyvinylpyrrolidone, 1 part to 4 parts of glycerin monostearate, 6 parts to 12 parts of dodecyl diethanolamide, 2.6 parts to 5 parts of glycol ether and 45 parts to 55 parts of water. Multiple surface active agents are compounded to form the metal cleaning agent, and the metal cleaning agent has the synergistic effect, has the properties of diffusion, emulsification, permeation, acid resisting, alkali resisting, hard water resisting and the like, and is high in cleaning capacity, free of metal corrosion, free of combustion and explosion, and free of environmental pollution.