Biodiesel with low temperature liquidity and preparation method of biodiesel

The invention discloses a biodiesel with low temperature liquidity and a preparation method of the biodiesel. The biodiesel with low temperature liquidity comprises 2.5-30 percent by volume of direct coal liquefaction hydro-upgraded modified full-fraction oil and 70-97.5 percent by volume of illegal cooling oil biodiesel. The preparation method of the biodiesel comprises the step: after mixing the illegal cooking oil biodiesel and the direct coal liquefaction hydro-upgraded modified full-fraction oil, and standing for 8-12 hours to obtain the biodiesel with low-temperature liquidity. According to the biodiesel with low temperature liquidity, the pour point, the cloud point, the flash point, the kinematic viscosity, the oxidation stability, the heat value, the density and the acid value of mixed oil are detected according to the GB_T20828-2007, and accord with relevant requirements of EN14214 and ASTMD6751 for the technical performance of the biodiesel through detection. Compared with the illegal cooking oil b