Abstract: To study the cause of abnormal CO emission in coal seams at igneous rock intrusion sites, and quantitatively describe the effects of thermal effects and time of magma intrusion on coal seam pore structure and gas adsorption capacity, the raw coal samples were treated with different temperature and time by anaerobic heating method, and the vitrinite reflectance experiment, mercury intrusion experiment and adsorption experiment were carried out. The results show that under the temperature and time conditions of this experiment, the effect of heat on the pore structure of coal sample is stronger than time; the thermal action increases the number of pores, total pore volume and large pore volume of coal samples, and the pores of coal samples change from semi-closed to fully open, and the connectivity between the voids is enhanced; the adsorption amount of CH₄ and CO in coal samples is proportional to the heat application temperature, and the thermal action changes the pore structure of the coal sample to improve the adsorption capacity of the coal sample for the two gases.