NOVELTY - Preparation of an immobilized cell catalyst taking waste foam as a carrier, comprises: (1) using Rhizopus oryzae fermentation culture medium, sterilizing and inoculating the culture; (2) preprocessing waste polyurethane foam; and (3) cell culturing.    USE - The method is useful for preparing an immobilized cell catalyst taking waste foam as a carrier, where the catalyst is used in preparing biological diesel oil (claimed).    ADVANTAGE - A whole-cell catalyst is prepared by immobilizing R. oryzae cells by using waste foam, so that not only can the waste polyurethane foam be recycled, but also the cell immobilization is simple in method and low in cost. When the prepared immobilized cell catalyst is used for catalyzing vegetable oil and fat such as soybean oil, barbadosnut seed oil, rubber seed oil and the like and waste oil and fat, the methyl esterification yield is up to over 90%; and the immobilized cell catalyst has better reusability, the lipase separation, extraction and purification processes are omitted, the production cost of the biodiesel is reduced on the process aspect, and efficient, clean and economic preparation and production of the biodiesel can be realized.    DETAILED DESCRIPTION - Preparation of an immobilized cell catalyst taking waste foam as a carrier, comprises: (1) using Rhizopus oryzae fermentation culture medium, sterilizing and inoculating the culture on the inclined surface of R. oryzae spore at 25-34 degrees C and under shaking at 180 rpm for 48-72 hours for further use as a seed solution, where, R. oryzae fermentation culture medium comprises: 1-2% of tryptone, 1-3% of soybean oil, 0.l% sodium nitrate (NaNO3), 0.1% potassium dihydrogen phosphate (KH2PO4), 0.05% magnesium sulfate (MgSO4), the initial pH is 5.5; (2) preprocessing waste polyurethane foam: cutting to 5-15 mm side length of the cube, using anti-steaming water for rinsing for some times at 121 degrees C for 20-30 minutes, then replacing distilled water repeatedly for two times, taking out and drying for further use; (3) cell culturing: in a 250 ml triangular flask adding 80 ml R. oryzae fermentation culture medium and 0.5-1.0 g of pre-treated waste foam, after inoculating with 0.5 ml of R. oryzae seed liquid obtained in the step (1), shaking at 180 rpm and culturing at 28 degrees C for 48-72 hours, growing cell-adsorbing foam, then developing and fixing, taking out and cleaning using water, drying at room temperature.