To explore the influence of water cement ratio, coal gangue coarse aggregate content(by mass), carbonization time and whether or not coal gangue coarse aggregate were calcined on the carbonation resistance of coal gangue aggregate concrete. The microstructure of calcined and non calcined coal gangue coarse aggregate concrete and the mechanism of its influence on carbonization were clarified by means of the scanning electron microscope(SEM). A multi parameter concrete carbonation model was established, which was suitable for different water cement ratio, coal gangue coarse aggregate content and carbonation time. The carbonation model was applied in the durability design of tunnel engineering structure. The results show that the carbonation depth of calcined and non calcined coal gangue coarse aggregate concrete increases with the increase of coal gangue coarse aggregate content, and it is linearly positive with the square root of coal gangue coarse aggregate and carbonization time. With low water cement ratio(such as 035), anti carbonization performance of calcined coal gangue coarse aggregate concrete is more significant than non calcined coal gangue coarse aggregate concrete. SEM study shows that the calcined coal gangue coarse aggregate concrete internal structure is denser than the non calcined coal gangue coarse aggregate concrete, which reduces the infiltration of carbon dioxide. The non calcined coal gangue coarse aggregate content in the pumping concrete should not be greater than 25% when the durability design of the tunnel structure. The research provides a theoretical basis for the anti carbonation performance analysis and engineering application of coal gangue coarse aggregate concrete.