The invention discloses a method for producing biodiesel by utilizing kitchen garbage, which comprises the following steps of: removing solid sundries out of the kitchen garbage; then adding water, pulping, regulating a pH value to be weak acidity and sterilizing; inoculating yeast cells to a kitchen garbage homogenate for liquid state fermentation, introducing gas at the temperature of 25-30 DEG C, stirring and fermenting for 70-75 hours; collecting the yeast cells after filtering a fermented liquor; crushing the yeast cells through a high-pressure homogenizer; adding the crushed cells into an extracting solvent, leaching, collecting an upper-layer organic solvent phase to obtain mixed oil, and evaporating and reclaiming the solvent in the mixed oil to obtain microbial grease; and obtaining the biodiesel through a methyl esterification reaction of the microbial grease. In the method of the invention, organic components in the kitchen garbage are converted into the microbial grease by adopting a microbial fermentation method to prepare the biodiesel, thereby solving the problem of insufficient raw material sources when the biodiesel is prepared by utilizing drainage oil, and laying a foundation for the resource utilization of the kitchen garbage and the industrialization development of the biodiesel.