Abstract: For the purpose of analyzing different working conditions of internal coating of gas pipeline and improving service life of coating', a test is carried out on dust wear, heated-air circulation and pig pulling with a full-seize equipment by simulating actual working conditions, and the parameter in the impact of the dust carried by gas, temperature change and pig running on the coating are obtained, respectively. Analysis results show that dust and pigging running have great impact on the wear of internal coating of pipe wall, and the thermal stress caused by temperature change has a relatively slight impact on the coating. Therefore, decreasing the concentration of dust and reducing the friction factor between pig cups and the internal coating, as well reducing the magnitude of interference and using light-type pig can all reduce the damage to the internal coating, which can improve the service life of internal coating for gas pipeline.