Acidic oil made by acidification and extraction of soapstock was used to produce biofuel in delayed coking apparatus. Through two pre-heatings of acidic oil in delayed coking apparatus, when the temperature of the coking drum reached 460 degrees C, the maximum yield of liquid oil (around 84%) was obtained, whereas the ratio of diesel and gasoline (about 5.3:1) was obtained. The liquid oil was separated by distillation to obtain the biofuel (205-360 degrees C). By comparing the basic properties of the obtained biofuel with 0# diesel and analyzing the basic properties of the resulted biodiesel-diesel blends, the results showed that the performance of the product was almost close to 0# diesel standards; when biodiesel content reached up to 20% in the blend, its properties (such as viscosity, density, and CFPP) changed slightly by comparing with 0# diesel.