TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The step of (b) comprises centrifuging a culture medium of Chlorella cells under a relative centrifugal force of 6000 for 4 minutes to remove the surplus liquid, where the heterophytic Chlorella cells are derived from Chlorella using protothecoides 0710 strains fermented by heterophytic high density, 30-60 wt.% of the oil content and 15-108 g/l of the dry well weight. The step of (c) comprises putting dried Chlorella powder, grinding solvent and grinding medium balls into a nylon ball mill tank, mixing Chlorella powder, grinding solvent and grinding medium balls with the ratio of Chlorella powder (g) to grinding solvent (ml) to grinding medium balls of 30:30:200-400:500, and ball milling the mixture into a planetary ball mill at 100-200 revolutions per minute. The nylon ball mill tank is sealed with the mixture. The step of (d) comprises crushing Chlorella cells ultrasonically with isopropanol into the ball mill tank under a frequency of 20 KHz, where the working time of ultrasonication is 40 minutes. The step of (e) comprises centrifuging the crushed cells under the centrifugal force of 6000 for 4 minutes, precipitating the mixture to remove the cell scraps and extracting the upper layer with Chlorella grease solvent. The step of (f) comprises decompressing and distilling the extracted Chlorella grease solvent at 65 degrees C, and fully evaporating and recovering the distilled extract with isopropanol to obtain crude Chlorella neutral grease. The step of (g) comprises adding n-hexane into extract grease, where the ratio of extract solvent to grinding solvent is 1:1, stewing the extract to separate polysaccharide and proteins, and taking upper extraction solvent to obtain a crude Chlorella neutral grease at a temperature of 60 degrees C after evaporating n-hexane. Preferred Components: The grinding solvent is ethanol, isopropanol or n-hexane. The eluting solvent is chloroform, isopropanol or n-hexane, where the ratio of grinding solvent to eluting solvent is 1:10. The zirconia grinding medium balls are filtered and separated. The frustule biomass has a moisture content of 60-70%. The grinding medium balls are zirconia balls with diameter of 5-10 mm. The moisture content of the wet Chlorella biomass is equal to the constant weight of drying wet Chlorella before drying.