NOVELTY - Method (M1) for producing microbial oil, involves crushing maize straw, sieving, adding water and sulfuric acid, performing filtration or centrifugation, adding cellulase, performing enzymolysis, and performing filtration or centrifugation to obtain supernatant, mixing processed material, adding sugar, centrifuging mixture, performing microbial oil fermentation, drying microbial cells, extracting, adding microbial oil into reactor, adding methanol, reacting mixture, separating and drying mixture.    USE - The method (M1) is useful for producing microbial oil by fermenting maize straw as a raw material. The method (M2) is useful for esterifying the microbial oil (claimed). The microbial oil is used as biodiesel.    ADVANTAGE - The method enables to produce various biologically fermented products.    DETAILED DESCRIPTION - Method (M1) for producing microbial oil by fermenting maize straw as a raw material, involves (a) crushing maize straw, sieving crushed material using 40-200 mesh sieve, adding corn straw powder into reactor, adding water, where the weight ratio of corn powder and water is 1:8-14, adding 0.5-1.25 vol.% sulfuric acid, maintaining at 100-160 degrees C for 60-150 minutes, and performing filtration or centrifugation, (b) adding residue obtained in step (a) and water into reactor, where the weight ratio of residue and water is 1:6-12, adding 25 floating-point unit (FPU)/g cellulase, performing enzymolysis at 40-60 degrees C for 50-80 hours, where the enzyme has activity of 80-160 IU/ml, performing filtration or centrifugation to obtain supernatant, (c) mixing processed material obtained in step (a) and (b), adding 60-80 g/l sugar, adjusting pH of the mixture to 6-7.5 using calcium hydroxide, centrifuging mixture at 40-70 degrees C for 20-30 minutes, and removing precipitate to obtain hydrolyzate, (d) performing microbial oil fermentation by (i) preparing seed culture liquid by obtaining Mortierella isabellina spores, adding into 2-3 ml sterilized water, gently shaking, inoculating into suspension into potato dextrose medium, performing shake culture at 28-30 degrees C and 80-100 revolutions per minute for 20-24 hours to obtain seed liquid, where the medium is prepared by mixing 1000 ml 20% potato juice, 20 g glucose, 3 g Monopotassium phosphate, 1.5 g Magnesium sulfate heptahydrate, where the pH is 6, and sterilizing medium at 121 degrees C for 15 minutes, and (ii) performing fermentation by adding 0.8-1.4 g/l ammonium sulfate and 6-10% seed liquid to hydrolyzate, fermenting mixture at 28-30 degrees C and 120-200 rpm for 72-120 hours, filtering fermented material to obtain microbial cell oil, (e) drying microbial cells, extracting cells by supercritical carbon dioxide extraction at 30-45 degrees C and 20-35 MPa for 1-3 hours, where the concentration of carbon dioxide flow rate is 20-25 kg/hour, and filtering mixture, and (f) adding microbial oil into reactor, adding methanol, where the molar ratio of microbial cell and methanol is 1:8-14, adding 0.5-1.4 %mass potassium hydroxide, reacting mixture at 400 rpm and 55-70 degrees C for 1-3 hours, allowing mixture to stand, washing mixture using water, separating and drying mixture. An INDEPENDENT CLAIM is included for method (M2) for esterifying the microbial oil.