The soil frost and bulge problem should be solved if the gas pipeline is laid underground, where the so low temperature by the gas throttle especially in winter can lead to pipeline safety problem. Heat pipes are used here to transfer heat of the deeper constant soil layer to the zone near the pipeline. The coupled equations of the moisture and energy equation are established. Given the gas pipeline size, the gas flow rate, the soil and weather conditions, considering the tentative optimal heat pipe arrangement, the soil moisture distribution and temperature field are obtained, a critical condition is analyzed....