NOVELTY - Biodiesel is produced by cleaning rape seed, drying until water content is 5-8%, freeze-drying at - 25 to - 20 degrees C for 16-18 hours, drying at 50-60 degrees C for 5-6 hours, adding 0.3-0.5 wt.% water to 6-7 pieces dried seeds, grinding for 20-30 minutes, drying at 50-60 degrees C until water content is 15-18%, grinding, screening using 10-20 mesh sieves, milling to obtain primary crude oil and seed cake, adding 20-30 wt.% water to primary crude oil, steam heating a 60-70 degrees C, stirring at a speed of 100-155 revolutions/minute for 30-40 minutes, and setting aside for 5-6 hours to form water layer and oil layer.    USE - Method of producing a biodiesel (claimed).    ADVANTAGE - The method is environment-friendly, guarantees pure oil, and has improved yield than existing method by as much as 5-6 wt.%.    DETAILED DESCRIPTION - Biodiesel is produced by cleaning rape seed, drying until water content is 5-8%, freeze-drying at - 25 to - 20 degrees C for 16-18 hours, drying at 50-60 degrees C for 5-6 hours, adding 0.3-0.5 wt.% water to 6-7 pieces dried seeds, grinding for 20-30 minutes, drying at 50-60 degrees C until water content is 15-18%, grinding, screening using 10-20 mesh sieves, milling to obtain primary crude oil and seed cake, adding 20-30 wt.% water to primary crude oil, steam heating a 60-70 degrees C, stirring at a speed of 100-155 revolutions/minute for 30-40 minutes, setting aside for 5-6 hours to form water layer and oil layer, separating oil layer, freeze-drying at - 5 to - 3 degrees C for 3-5 hours, filtering, grinding the filter cake, adding 1-5 wt.% decolorizing agent, mixing, soaking mixture in 10-15 vol.% hydrochloric acid solution for 2-3 hours, adding sodium hydroxide solution having a concentration of 10-12 wt.%, setting aside for 2-3 hours, adding hydrogen peroxide solution having a concentration of 10-15 vol.%, setting aside for 1-2 hours, adding deionized water, centrifuging at a speed of 10000-12000 revolutions/minute for 10-15 minutes, grinding, washing with water, and purifying. The decolorizing agent comprises diatomite and activated carbon having a weight ratio of 2-3:1.