NOVELTY - Bio-diesel synthesizing device comprises base oil storage tank, two current stabilizers, A-type additive storage tank, B-type additive storage tank, water storage tank, circulation pump, finished oil storage tank, and controlling device. The current stabilizers are connected in parallel through a column having an outlet mounted with plate heat exchanger. The plate heat exchanger has upper part connected with the base oil storage tank, an end outlet connected to water measuring tank, and another end outlet connected to finished oil storage tank.    USE - A device for synthesizing bio-diesel in large scale production.    ADVANTAGE - The device is environmentally-friendly; saves petroleum resources; and reduces discharge of pollutants.    DETAILED DESCRIPTION - Bio-diesel synthesizing device comprises base oil storage tank, two current stabilizers, A-type additive storage tank, B-type additive storage tank, water storage tank, circulation pump, finished oil storage tank, and controlling device. The current stabilizers are connected in parallel through a column having an outlet mounted with plate heat exchanger. The circulation pump is mounted in outlet pipeline of the second current stabilizer. The plate heat exchanger has upper part connected with the base oil storage tank, an end outlet connected to water measuring tank, and another end outlet connected to finished oil storage tank. Each of the additive storage tanks is connected to one current stabilizer through additional solenoid valve, additive flow meter, additive conveying pump, additive measuring pump and additive feeding solenoid valve. A static mixer is mounted in the column. The current stabilizers comprise increasing section, shrinking section, traverse baffle and electric heater. The traverse baffle is welded on main bodies of current stabilizers. The first current stabilizer has increasing section mounted with observation window. The second current stabilizer has top end with exhaust fan and exhaust pipeline, and shrinking section mounted with observation window. The column is mounted with thermometer and temperature sensor, and an external surface with insulation material. The solenoid valves, flow meters, pumps and electric heaters are connected with the controlling device.