NOVELTY - A new method for preparing biodiesel by extracting rice bran oil in-situ comprises adding alcohol (or mixture of alcohol and solvent) and acid catalyst into a reaction kettle, adding rice bran into an extraction tank, adding dewatering agent and alkali catalyst into an alkali tank, opening valves 2-1 and 2-2, heating and reflowing, extracting rice bran oil, esterifying fatty acid in-situ, closing valves 2-1 and 2-2, while opening valves 5-1 and 5-2, reflowing and reacting, recycling alcohol/solvent, using hot water to wash product, cooling and drying oil layer to obtain product.    USE - The new method is useful for preparing biodiesel by extracting rice bran oil in-situ (claimed).    ADVANTAGE - The new method for preparing biodiesel by extracting rice bran oil in-situ avoids problem as saponification caused by over high of partial alkali-generated water by synchronous water removing process and gradual acid-alkali transition process, and eliminates complicated material treatment process in preparing biodiesel by acid-alkali technique to reduce production cost of biodiesel.    DETAILED DESCRIPTION - A new method for preparing biodiesel by extracting rice bran oil in-situ comprises adding alcohol (or mixture of alcohol and solvent) and acid catalyst by proportion into a reaction kettle, adding rice bran into an extraction tank, adding dewatering agent and alkali catalyst into an alkali tank, opening valves 2-1 and 2-2, heating and reflowing, extracting rice bran oil, esterifying fatty acid in-situ, closing the valves 2-1 and 2-2 after 1-5 hours, while opening valves 5-1 and 5-2, reflowing and reacting for 3-5 hours, after ending reaction, recycling alcohol/solvent, using hot water to wash product, cooling and drying oil layer to obtain product. Further purification can distil the product under the condition of reducing pressure and distillation cut can be collected at 140-230 degrees C and 0.098 MPa.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of new method for preparing biodiesel by extracting rice bran oil in-situ.