Abstract: The operation process of pipeline will interfere with the natural transfer of soil temperature and moisture, in order to visualize the disturbance of moisture-heat transfer on frozen soil state, this paper carries out numerical analysis for the mechanics changes in frozen soil and analyzes the small changes of frozen soil framework and pore structure caused by moisture-and heat transfer. According to the simulation results, the direct effect of moisture and heat-transfer on frozen soil is that in months with low ambient temperatures, the greater the frozen soil stress is, the smaller the strain is, and in months with high ambient temperatures, the smaller the frozen soil stress is, the greater the strain is. These trends are due to the change of heat transfer amount between pipeline and frozen soil, and moisture-heat transfer of frozen soil caused by the change of ambient temperature. The essential reason is that as the temperature rises, the structure of gum in pore is destroyed, and pore structure is extruded and deformed, which appear that the porosity and pore size become small, moisture transfer accelerates, causing stress and pressure on frozen soil framework, and reducing the framework strength.