NOVELTY - Manufacture of low temperature improver of epoxy fatty acid branch alcohol ester biological diesel oil comprises using natural oil and branch alcohol as raw materials; producing fatty acid branch alcohol ester in the presence of catalyst; reacting to obtain raw product of fatty acid branch alcohol ester; distilling; heating; mixing fatty acid branch alcohol ester and formic acid; adding epoxy catalyst; dropping hydrogen peroxide; heating obtained fatty acid branch alcohol ester and splitting the phase; washing upper oil by alkaline and water; and distilling to remove water.    USE - Method of manufacturing low temperature improver of epoxy fatty acid branch alcohol ester biological diesel oil.    ADVANTAGE - The method introduces the polar group to fatty acid ester bound chain and inner double-bond structure. The solution mixed uniformly and easily with biological diesel oil is beneficial for the further growth of solid crystals. After the different oil biological diesel oils are mixed with improver, the low temperature mobility is improved dramatically. The reducing amplitude of condensing point and the filtering point is 5-15 degrees ; the heat value is increased; and the adhesiveness is reduced.    DETAILED DESCRIPTION - Manufacture of low temperature improver of epoxy fatty acid branch alcohol ester biological diesel oil comprises:    (A) using natural oil and branch alcohol as raw materials; producing fatty acid branch alcohol ester in the presence of a catalyst, where the mole ratio of natural oil and branch alcohol is 1:1-10, and the amount of catalyst is 0.8-5% of the weight of natural oil; performing reaction for 20-120 minutes at 45-100 degrees C; obtaining the raw product of fatty acid branch alcohol ester; distilling; separating the unreacted branch alcohol; heating and layering the rest of liquid to obtain the upper fatty acid branch alcohol ester and lower glycerol, where the branch alcohol is 3-8C primary alcohol branch alcohol or secondary alcohol branch alcohol without branch on a carbon atom;    (B) mixing the fatty acid branch alcohol ester and formic acid at mass ratio of 100:5 to 30; adding an epoxy catalyst amounting at 0.8-3% of weigh of oil; stirring; increasing the temperature to 40-50 degrees C; dropping 20-40 mL/hour hydrogen peroxide; increasing temperature to 55-70 degrees C; maintaining temperature for 2-6 hours; and obtaining the raw product of epoxy fatty acid branch alcohol ester; and    (C) heating the fatty acid branch alcohol ester and splitting the phase; recycling the formic acid in lower water phase; washing upper oil by alkaline and water; reducing the pressure; distilling the solution to remove water; and obtaining epoxy fatty acid branch alcohol ester.    An INDEPENDENT CLAIM is included for use of biological diesel oil improver comprising uniformly mixing low temperature improver with biological diesel oil at 0.5: 3%.