Abstract: In order to research the influence of coal particle size and adsorption equilibrium pressure on residual gas content of anthracite, we tested the residual gas content of 0～0.25 mm, 0.25～0.5 mm, 0.5～1 mm, 1～3 mm, 3～6 mm 5 different particle sizes and 0.5, 1.0, 1.5, 2.5 MPa 5 kind different adsorption equilibrium pressure in the laboratory, analyzed the influence of particle size and adsorption equilibrium pressure on residual gas content. Test results show that the residual gas content increases with the increase of particle size, there is a positive correlation between coal particle size and residual gas content, but it has the maximum particle size. The increase of residual gas content decreases with the increase of particle size. The variation of residual gas content with particle size agrees with Langmuir's function. The residual gas content tends to be fixed when the particle size is more than 6 mm; the residual gas content has no obvious change with the increase of adsorption equilibrium pressure, the adsorption equilibrium pressure has little influence on the residual gas content. By comparing the calculated values with the experimental ones, based on the influence of particle size on residual gas content, the existing residual gas content calculation formula and compensation method are proposed.