TECHNOLOGY FOCUS - BIOLOGY - Preferred Component: The lipase microbe is fungus, bacterium or yeast. The fungus can be Rhizopus chinensis or Penicillium expansum. The bacterium can be Pseudomonas aeruginosa or Pseudomonas cepacia. The yeast can be Yarrowia lipolytica. The weight ratio of fermentation culture medium to the lipase microbe is 10:1-10:4.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The mol concentration of phosphate buffer solution is 0.1 mol/L and the pH is 7. Preferred Method: The phosphate buffer solution is prepared by providing 0.68 g monopotassium phosphate in container, and 0.116 g sodium hydroxide solid, putting into the container, adding 50 ml water, dissolving two solids in the container, testing the pH value of the solution, and when pH is higher than 7, and slowly dipping diluted hydrochloric acid to the container to adjust the pH, after the pH reaches 7, keeping the volume to 100 ml.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The cane residue is prepared by obtaining cane, removing two ends, keeping the central part, peeling and cutting the peeled cane into cane cubes with 1-2 cm3, putting the cane cubes to the oven for 12 hours at 60 degrees C, crushing the baked cane cubes by the crusher to obtain the cane residue, rinsing the cane residues by the distilled water, removing sugar and putting into the oven for 12 hours at 60 degrees C, sieving the baked crude cane residue by 80 mesh and 30 mesh of screen, putting the 30 sieve on the 80 sieve, selecting the cane residue between two sieves and obtaining the product. Sterilization in pressure sterilizing boiler is for 20 minutes at 121 degrees C. The fermentation culture medium is added with lipase microbe to solid ferment. The solid fermentation product containing lipase is obtained by adding the lipase microbe in exponential phase to the culture medium, stirring and sealing, culturing in the shaking bed for 84-120 hours at 150 revolutions/minute (rpm) at 28 degrees C. The freeze drying is vacuum freeze drying at 20 Pa and drying temperature of - 50 degrees C for 1-12 hours; and before freeze drying, pre-cooling the solid fermentation product in the super-low fridge for 20 minutes at - 70 degrees C. Normal hexane or petroleum ether or chloroform/normal hexane mixed solvent is used as extractor, and extracting for 0.5 hours, where ratio of freeze dried fermenting product to the extractor is 1:10-15. The biodiesel is prepared by taking freeze dried and degreased solid fermentation product as catalyst; mixing soybean oil with absolute ethyl alcohol at a mol ratio of 1:1-1:8, preferably 1:4; adding phosphate buffer solution, where mass ratio of phosphate buffer solution to soybean oil is 1-10:100, preferably 5:100, and mass ratio of freeze dried and degreased solid fermentation product to soybean oil is 5-20:100, preferably 10:100; stirring for 10 minutes at 40 degrees C; adding the freeze dried and degreased solid fermentation product as catalyst; stirring for 84-120 hours at 40 degrees C; centrifuging for 5-10 minutes at 12000 rpm, rinsing, distilling and recovering the ethanol to obtain the biodiesel.