The combined treatment of EICP (enzyme-induced carbonate precipitation) and xanthan gum can improve the mechanical properties of seasonally frozen silty soil, providing a novel approach for its development and utilization. Freeze-thaw cycle tests, UCS (unconfined compressive strength) tests, direct shear tests, SEM (scanning electron microscopy), and XRD (X-ray diffraction) analyses were conducted in the laboratory. The mix proportion of xanthan gum-EICP improved silty soil was optimized using response surface methodology, and the macroscopic mechanical properties and microstructure of the improved silty soil under freeze-thaw cycles were investigated. The results indicate that the mechanical properties of xanthan gum-EICP improved silty soil samples were significantly enhanced. Considering the variations in strength parameters of the EICP-xanthan gum improved silty soil samples, the optimal strength parameters were achieved at a curing period of 7 days, a xanthan gum content of 1.465%, and a cementing solution-to-soybean urease volume ratio of 1∶1. Xanthan gum-EICP improved silty soil can mitigate internal damage caused by freeze-thaw cycles and effectively improve shear strength. Microstructural analysis elucidated the failure process of EICP-xanthan gum improved silty soil samples under freeze-thaw cycles and the factors contributing to the reduction of various strength parameters.