The invention discloses a method for producing transformer oil through kitchen waste grease. The method includes the following steps of (1) crystallizing degreasing; (2) adsorbing decoloring; (3) distilling deacidifying; (4) molecular-sieve dielectric-loss removing; (5) rectifying moisture removing. According to the method, it is achieved that insulation deacidification transformer oil is continuously, industrially and industrially produced through the kitchen waste grease, a new path is developed for utilization of the kitchen waste grease, and a phenomenon that the kitchen waste grease flowsto dining tables is thoroughly avoided; chemical alkali refining is not required, environmental pollution is avoided, dielectric loss is removed through a molecular sieve, the acid value of grease isfurther reduced, the dielectric loss of the transformer oil can be smaller than or equal to 1.0%, and the acid number of the transformer oil can be smaller than or equal to 0.03 mg KOH/g; the yield of the transformer oil is greatly increased, and is increased by 30% to 35% than chemical alkali refining yield; it is completely avoided that oil-containing and soap-containing wastewater is discharged; zero pollution and zero discharging are achieved, and the method is an innovative technology for producing the insulation deacidification transformer oil, has broad application prospects and the practical application value, and is environmentally friendly.