The invention relates to flame-retardant, acid-proof, alkali-proof and anti-bacterial lubricating oil for a mechanical bearing. The flame-retardant, acid-proof, alkali-proof and anti-bacterial lubricating oil consists of the following components in part by mass: 580-620 parts of base oil, 60-64 parts of glycerin monostearate, 56-60 parts of epoxidized soybean oil, 60-64 parts of isophorone diisocyanate, 56-60 parts of triethoxyisobutylsilane, 60-64 parts of sodium molybdate, 56-60 parts of oleic acid polyoxyethylene ester, 62-66 parts of dioctyl phthalate, 56-60 parts of olychloroprene, 60-64 parts of adipic acid pentaerythritol ester, 56-60 parts of white oil, 60-64 parts of zinc stearate, 56-60 parts of inositol hexaphosphate, 60-64 parts of isothiazolinone, 56-60 parts of sodium diacetate, 60-64 parts of methylisothiazolinone, 56-60 parts of pulverous coal, 60-64 parts of alumina, 56-60 parts of dibulytin dilaurate, 60-64 parts of tetrabutyl titanate, 56-60 parts of naphthenic acid, 60-64 parts of dipropylene glycol monomethyl ether and 56-60 parts of cobalt aluminate powder. The lubricating oil has good corrosion-resistant, flame-retardant and anti-bacterial properties.