NOVELTY - Preparing high-efficient lipase expression bacterial strain, comprises e.g. (a) cloning hygromycin resistance expression vector and recombinant plasmid to obtain hygromycin resistance target plasmid, and (b) respectively amplifying Penicillium lipase gene (PEL), Aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase promoter (PgpdA) and terminator of tryptophan synthase of Aspergillus nidulans (TtrpC) to obtain PEL gene expression vector with strong promoter.    USE - The method is useful for preparing high-efficient lipase expression bacterial strain, which is useful for producing biological diesel (all claimed).    DETAILED DESCRIPTION - Preparing high-efficient lipase expression bacterial strain, comprises (a) cloning hygromycin resistance expression vector and recombinant plasmid to obtain hygromycin resistance target plasmid, (b) respectively amplifying Penicillium lipase gene (PEL), Aspergillus nidulans glyceraldehyde-3-phosphate dehydrogenase promoter (PgpdA) and terminator of tryptophan synthase of Aspergillus nidulans (TtrpC) to obtain PEL gene expression vector with strong promoter, (c) inserting the PEL gene expression vector into recombinant plasmid of hygromycin resistance to obtain the hygromycin selection marker of PEL gene over-expression carrier, and (d) dissolving the mixture containing hygromycin selection marker of PEL gene over-expression carrier into Agrobacterium rhizogenes, transferring gene engineering bacteria using Agrobacterium mediated transformation method for PEL gene expression cassette into green strain. An INDEPENDENT CLAIM is included for producing biological diesel oil by lipase, comprising (a1) pretreating raw material by filtering biological oil to remove impurity and then stirring to obtain emulsion at a stirring speed of 5000-10000 revolutions per minute (rpm) for 5-15 minutes, (a2) adding oil and methanol or alcohol into a reaction container in a mole ratio of 1:1-3, adding modified Penicillium expansum lipase and organic solvent under reaction condition at 20-50 degrees C, mixing and reacting for 6-24 hours, and again adding methanol or ethanol and grease in a mole ratio of 1:1-3, and (a3) separating the lipase from the reactant after the reaction is finished, centrifuging the reaction product, standing and separating the lower layer, which is crude glycerin, distilling upper layer of the liquid, and recovering the organic solvent to obtain the finished biodiesel.