Abstract: In order to study the influence of electrostatic field on gas adsorption, constant voltages (0、4、8、12、16 kV) were exerted with EST802 electrostatic generator on different coal samples, then WY-98B adsorption constants tester was used to determine the gas adsorption amount and Langmuir adsorption constants a and b of different coal samples. The results showed that under the same experimental condition, the gas adsorption amount increased with voltages increasing before and after adding electrostatic field,b value changed significantly relative to a and had an increasing trend. For different coal rank and different damage types, the influence degree of the electrostatic field on coal samples included that the middle-high deterioration bituminous coal was greater than the anthracite coal, the soft coal was greater than hard coal, and the coal rock components had a greater influence on electrostatic field response of coal samples which contained gas.