Abstract: The direct current field was used as the physical field. An experimental apparatus affecting the adsorption of coal gas with the current field weakening was developed; the experimental study is about the adsorption of coal gas under the direct current field. The adsorption property of the saturated adsorption capacity and the adsorption constant were analyzed. The experimental results were as follows: the coal gas adsorption can be weakened by the voltage. The adsorption property of coal gas is still followed with Langmuir equation under the direct current field. The adsorption capacity under the voltage treatment is larger than that under the frequency treatment. With the increasing of the voltage and frequency, the saturated adsorption capacity reduced with line law and the adsorption constant reduced with exponential law.