The stabilization effect and mechanism of the soil stabilizer based on the ternary system of ordinary Portland cement， granulated blast furnace slag and sodium sulfate （OPC-GBFS-NS） on two different soils were studied. The results show that the soil stabilizer has good stabilization effects on both common surface soil and seaside silt to bring high unconfined compressive strength of the stabilized soil， and assumes good consolidation effects on the heavy metal ion Cd²⁺ in the soil， accordingly to significantly reduce the dissolution of Cd²⁺. The stabilization effect of the soil stabilizer is mainly due to its rapid hydration in the soil to generate a large number of slender ettringite crystals， which tightly connect with soil particles.