The invention discloses emulsified lubricating oil for machining, and relates to the technical field of machining. The emulsified lubricating oil is prepared from, by weight, 6-20 parts of sodium hydroxide mother liquor, 25-55 parts of 3# naphthenic acid, 1 part of emulsifier benzene-80, 1 part of emulsifier tween-80, 2-8 parts of middle molecular anolamines, 13-35 parts of basic oil, 1 part of Ta and Tb composite rust inhibitor, 5 parts of phosphate ester, 0.5 part of titanium dioxide nano-particle, 1 part of dithiopyro phosphate, 0.5 part of sodium metaborate, 5 parts of poly a-alkene T803A, 0.2 part of calcium alkyl salicylate T109, 0.3 part of sulfurized calcium alkyl phenolate T115A, 0.3 part of diaIk eny I succinimide T152, 0.2 part of succinic acid pentaerythritol ester L117, 3 parts of zinc dialkyl dithiophate (ZDDP), 1 part of benzotriazole T706 and 1 part of molybdenum dialkyl dithiophate (Mo DDP). High-qualified emulsified lubricating products can be provided for machining industries such as metal cutting and metal rolling.