The aim of this research is to investigate the influence of bubble preparation factors on the properties of foamed mixture soil using river sludge. We examined the foaming performance of different foaming agents and prepared a mixed foaming agent F by optimizing the proportions of foaming agents. On this basis, we analyzed the physical and mechanical properties of the foamed mixture soil with river sludge as raw material through contrast test. Results showed that different types and qualities of foam agents have apparent influence on the properties of the mixture soil. Protein foaming agent is of poor ability in stabilizing foams, hence could not meet density requirement. Under the same density, the lightweight soil prepared by foaming agent F is superior to that by foaming agent K12A in terms of strength, strain at failure and E₅₀. In conclusion, good performance of foam-stabilization, expansion rate of foam, uniform bubbles, and co-existence with soil slurry would be beneficial to improving the comprehensive performance of light-weighted soil.