Abstract: The application effect of electrochemical method to enhance gas drainage in coal seam mainly depends on the rationality of engineering design and parameter selection. In this paper, the method of laboratory experiment is used to electrochemically modify the lean coal with H2SO4, Na2SO4 and NaOH. The gas adsorption and desorption characteristics of the coal samples before and after modification are tested. The changes of pore structure and surface group of the lean coal samples after modification are analyzed by the low temperature liquid nitrogen adsorption test and infrared spectrum test. The results show that the saturated adsorption capacity of the unmodified coal sample is 30.03 mL/g, the Langmuir pressure of the unmodified coal sample is 0.88 MPa, and the final desorption rate of unmodified coal sample is 83.20%; after the electrochemical modification of H2SO4, Na2SO4 and NaOH, the saturated adsorption capacity of the coal sample is 23.70 mL/g, 26.67 mL/g, 32.79 mL/g, respectively; the Langmuir pressure of the coal sample is 1.15 MPa, 1.05 MPa, 0.80 MPa, respectively, and the final desorption rate of coal sample is 90.10%, 87.84% and 81.71%, respectively; the lean coal after electrochemical modification of H2SO4 electrolyte has the smallest specific surface area, the largest average pore diameter and the largest number of oxygen functional groups, so the effect of inhibiting gas adsorption and strengthening gas desorption is the best.