In the investigation,a consolidated drained tri-axial comparison test was performed to analyze the undis-turbed soil,the heavy metal-contaminated soil and the heavy metal-contaminated soil with the organic curing agent(epoxy curing agent of 1.5%,epoxy curing catalyst of 2.6%，thinner of 1.0%)under the low confined pressuresof 90,120,240kPa and the relatively high confined pressures of 600,900,1200kPa,and the mechanical volu-metric-change characteristic curves of the three kinds of soils were drawn up.The results show that the organic cu-ring agent can dramatically improve the strength of the heavy metal contaminated soil,and effectively ameliorate itsmechanical behavior of expanding under a low confined pressure and of contracting under a relatively high confinedpressure.In addition,a two-yield-surfaces volumetric-change constitutive model of the heavy metal metal-contami-nated soil is established based on the Pietruszczak hardening rule.This model overcomes the deficiency of the singleyield surface model that can't be used to describe the critical state of the volumetric change of the heavy metal-con-taminated soil,and it also reflects the volumetric change more reasonably.