NOVELTY - Ester exchange reaction comprises conveying oil material, methanol, and sodium hydroxide solution into ester exchange raw material mixing tank, agitating, and processing the ester exchange reaction in a continuous pipe reactor; continuously and calculatedly conveying the pre-esterified animal grease and plant oil through static mixer by ester exchange reaction feeding pump, conveying material into ester exchange combined reactor, and raising temperature of the reaction material; and conveying the material into a reactor to perform thermal isolated ester exchange reaction.    USE - Ester exchange reaction for biodiesel production (claimed).    ADVANTAGE - The method provides esterified product that does not need to be neutralized and washed to reduce discharging of wastewater; can be performed continuously; and has improved production efficiency. Conversion rate of glyceride is 98.5%. The device used in the method has reduced reaction volume, thus providing reduced investment cost.    DETAILED DESCRIPTION - Ester exchange reaction for biodiesel production comprises:    (A) conveying oil material, methanol, and sodium hydroxide solution into ester exchange raw material mixing tank at 0.5-1 MPa and 64-66 degrees C, agitating to mix mutually un-dissolvable oil material, methanol, and catalyst solution, and processing the ester exchange reaction in a continuous pipe reactor for 1-2 hours;    (B) continuously and calculatedly conveying the pre-esterified animal grease and plant oil through static mixer by ester exchange reaction feeding pump after they leave the raw material mixing tank, conveying the material into an ester exchange combined reactor through a raw material pre-heater, and raising the temperature of the reaction material to 240-250 degrees C using carrier; and    (C) conveying the material into a reactor to perform thermal isolated ester exchange reaction, and keeping the material in the reactor for 20-30 minutes.    An INDEPENDENT CLAIM is included for a device for ester exchange reaction method in biodiesel production.