The invention discloses a method for improving the 
biomass and oil fat yield of microorganisms. The method comprises the following steps: (1) carrying out activated culture: respectively inoculating 
chlorella pyrenoidosa and 
rhodotorula glutinis cells into a culture medium, carrying out activated culture to a logarithmic phase, and taking a product as a seed solution; (2) respectively inoculating 
chlorella pyrenoidosa and 
rhodotorula glutinis into a 
shake flask according to different proportions, wherein each 
shake flask is internally filled with a culture medium, putting the shake flasks into a lighting 
shaker, and culturing; (3) respectively inoculating 
chlorella pyrenoidosa and 
rhodotorula glutinis cells into a BG11 culture medium, wherein the ratio of 
chlorella pyrenoidosa cell number to the rhodotorula glutinis 
cell number is equal to 3: 1, and the BG11 
culture mediums contain 1.6g / L of 
yeast extract and have different glucose concentrations; putting the inoculated shake flasks into the lighting 
shaker, and culturing for 12 days; (4) after the culture is finished, centrifuging microbial cells, washing and carrying out 
freeze drying to obtain 
powder; the 
powder can be used for measuring and evaluating the 
dry weight concentration, total 
lipid content, 
fatty acid content and yield of the 
biomass. The method has the advantages that the 
biomass and oil fat yield of the oil-containing microorganisms are remarkably improved by utilizing a mixed culturing mode, and are 3-4 times or more than those of microorganisms cultured under a single culture condition; the method is relatively simple and convenient, and the 
energy consumption and the production cost are effectively reduced.