Abstract: With the acceleration of China's construction industry, the foundation pit support sector has also experienced rapid development. As foundation pits become higher, larger, and deeper, the requirements for deformation control and water sealing have become increasingly stringent. Particularly in areas with unfavorable geological conditions such as thick silt and sand layers, natural strata often fail to meet the stability requirements for foundation pit engineering. To address these challenges, soil solidification technology has been introduced into foundation pit engineering, aiming to provide a more economical, environmentally friendly, and efficient solution. This study is based on a certain foundation pit project in Zhongshan, adopting a research method combining numerical simulation, field tests and engineering applications and systematically investigates the application effect of solidified soil technology in foundation pit support. Through the solidification indoor test of high-water-content mucky soil, the strength exert rule of different solidifying agent mixing ratio is revealed; the numerical calculation model is constructed by using Midas GTS-NX software to analyze the whole process of foundation pit excav. The results of the study show that the 14 d unconfined compressive strength of the solidified soil with a cement content of 12% can reach 0.8 MPa; the comparison between the numerical simulation and the field monitoring data shows that the horizontal displacement error of the support structure is controlled within 8% which verifies the reliability of the calculation method. This study provides an economical, environmentally friendly, and controllable new support solution for foundation pit engineering in soft soil areas, demonstrating promising prospects for widespread application.