The invention relates to a method for utilizing the microorganism technology for treating a saturated sand foundation. The method is characterized in that the microorganism is a fungicide mixture formed through three fungicides including Bacillus sphaericus, Bacillus deserti CCTCC AB 207173 (T) and Niastella populi CCTCC AB 208238 (T) according to the volume ratio of 1:1:1. The fungicide mixture, a culture medium, nitrate and water are mixed and stirred according to the proportion of 2:1:1:1 into seriflux, and the seriflux is poured into the sand foundation; and the denitrification reaction happens under the catalytic action of the microorganism, uniform nitrogen is generated in the saturated sand foundation, the saturability of the foundation is reduced, and the foundation liquefying performance is improved. Site grinding is not needed, construction is convenient, solid waste is used, pollution of the solid waste to the environment is reduced, the project cost is reduced, and good economic benefits and social benefits are achieved in the aspects of resources and environment protection. According to the method, the construction manufacturing cost is low, the method is ecological and environment-friendly, and the anti-liquefying capability after treatment is high.