Abstract: Microbially Induced Calcite Precipitation(MICP)technology can be used to solidify and stabilize heavy metal contaminated soil. This paper mainly studies the strength and chemical stability of MICP-solidified lead-contaminated soils under freeze-thaw cycles through unconfined compressive strength, ion leaching, and microscopic tests, and reveals its microscopic mechanism. The results show that with the increase in lead ion concentration, the unconfined compressive strength of the soil increases first and then decreases, and the lead ion leaching concentration increases. With the increase in freeze-thaw cycles, the strength of the soil decreases and tends to be stable, and the lead ion leaching concentration increases. After the freeze-thaw cycle, the main mineral components of solidified soil do not change; the number of small pores in the soil increases, and the number of large pores remains basically unchanged. Freeze-thaw cycles damage the calcium carbonate cementation and lead ion precipitation structure of solidified soil, resulting in the deterioration of soil properties.