The invention discloses a waterborne low-foam metal surface cleaning agent for thermal spraying. The waterborne low-foam metal surface cleaning agent comprises the following raw materials: a component A and a component B, wherein the component A and the component B are mixed at a volume ratio of 4:1 during preparation; in parts by weight, the component A comprises 4-8 parts of ethylenediaminetetraacetic acid, 11-18 parts of polyether, 10-15 parts of trihydroxyethyl amine, 1-4 parts of octadecenoic acid, 5-10 parts of dichloromethane, 10-17 parts of ethylene bis-stearamide, 5-8 parts of calcium alkylbenzene sulfonate, 2-4 parts of zinc dialkyl thiophosphate, 12-15 parts of benzotriazole, 4-6 parts of an antioxidant, 6-8 parts of a defoamer and 75-80 parts of water; in parts by weight, the component B comprises 14-16 parts of sodium carbonate, 3-8 parts of butanediol, 5-7 parts of sodium gluconate, 6-8 parts of triethylamine urea, 17-19 parts of polyoxyethylene aliphatic alcohol ether, 3-6 parts of alkanolamide and 40-55 parts of water. The waterborne low-foam metal surface cleaning agent can be used for radically cleaning dirt such as carbon powder, scrap iron, oil stains and the like formed on the outer surface of a metal workpiece due to machining; the cleaned metal outer surface is not integrally or locally corroded; the raw materials of the waterborne low-foam metal surface cleaning agent are all neutral products, so that the waterborne low-foam metal surface cleaning agent is mild in performance and does not contain chromate and nitrite; the waterborne low-foam metal surface cleaning agent is odorless, free of environmental pollution and harmless to a human body; at the same time, the waterborne low-foam metal surface cleaning agent is low in foam quantity, easy for rinsing and suitable for cleaning operation of an automatic cleaning machine.