The cemented polymer was used to solidify silt soil. The effects of polymer content， silt soil moisture， and curing time on the mechanical property of the silt soil have been investigated. The solidification mechanism of polymer for silt soil was demonstrated. The results indicate that polymer has a good consolidation effect on silt soil. The strength of solidified silt soil increases with the increase of polymer content， the decrease of silt soil moisture content and the increase of curing time. Polymer can effectively adhere to the surface of silt soil and fill voids between silt soil particles. Polymer can reduce the porosity ratio and improve the compactness of silt soil， so as to improve the strength and anti-permeability of silt soil mainly through adhesion， wrapping， filling， and bridging. No new compounds are produced in this process.