Abstract: Based on vegetable oil residue, the whole process of producing liquid organic fertilizer was designed by using biotechnology and physical-chemistry method. The research mainly introduced some technologies, including the determination of the target nutrient elements, the optimization of the hydrolysis conditions, the cultivation of the protease strains and the enhancement of the nutrient elements etc. The paper also expounded the principles, application conditions and research progress of the control methods, and proposed a new way which was low-cost for large-scale production of liquid organic fertilizer. The results can provide references for the resource utilization of organic manure.