In order to improve the utilization rate of soola residue and reduce the harm to the environment caused by soda residue storage, this paper proposed to use soda residue and fly ash stabilized clay, and add cement and lime to prepare soda residue-fly ash stabilized soil. Taking the maximum dry density, optimal water content, unconfined compressive strength (UCS) and shear strength parameters as the indexes, the orthogonal matrix analysis method was used to analyze the influence of soda residue, fly ash, cement and lime on the mechanical properties of soda residue-fly ash stabilized soil according to the influence weight. The results show that the fly ash content has the greatest influence on the maximum dry density. The soda residue content has the greatest influence on the optimum water content, 7 d UCS and the internal friction angle of 7 d shear strength. The lime content has the greatest influence on the cohesion of 7 d shear strength. The soda residue-fly ash stabilized soil has good strength performance. Based on the gradation mechanism of soda residue-fly ash stabilized soil and the cementation mechanism of cementitious materials, the orthogonal matrix analysis method is used to recommend the scope of application of the mix ratio, so that the soda residue-fly ash can better serve the actual project.