Method for producing biodiesel fraction from grease raw material

The invention relates to the field of biofuel production, and discloses a method for producing a biodiesel fraction from a grease raw material, and the method comprises the following steps: in the presence of hydrogen, carrying out first hydrotreatment and heat exchange treatment on the grease raw material to obtain a hydrotreatment effluent I; the hydrotreating effluent I is subjected to second hydrotreating, and a hydrotreating effluent II is obtained; carrying out gas-liquid separation on the hydrotreating effluent II to obtain liquid hydrocarbon, water and a gas stream; at least part of the liquid hydrocarbon is subjected to a hydroisomerization reaction, then separation is conducted, and diesel oil fractions are obtained. According to the method provided by the invention, the reaction with high reaction rate and large heat release in the grease hydrogenation process is completed in the reaction modules, and meanwhile, a plurality of heat exchange templates are additionally arranged between the reaction m