The invention discloses a method for controlling generation of TFA during oil deodorization without adding strong base. The method which is a method for lowering TFA in oil is provided aiming at a series of problems of high TFA generation capacity and low plant oil quality during the deodorization process of crude soybean oil. Lipase is utilized to enable free fatty acid in the oil to be in esterification with glycerin, so that content of the fatty acid in the oil can be lowered effectively; a process of adding NaOH in the process of oil deacidification is omitted, a discovery is that energy of fatty acid double bonds in the oil can be controlled effectively through a reasonable enzyme-process esterification deacidification process to influence content of produced TFA in the subsequent deodorization process, and only 0.42% of TFA content is generated in the deodorization process of the crude soybean oil; the key is that no NaOH is added in the process of deacidification, double bond activating energy of the fatty acid in the oil is unchanged, opportunities of isomerization of fatty acid double bonds in the oil are reduced, and generation of TFA in the deodorization process of the crude soybean oil is controlled effectively.