Abstract: Aiming at the shortcomings of the present laboratory research on imbibition effect of coal containing gas, the experimental platform was set up under the condition of constant pressure. Under constant pressure of the experimental system, imbibition effect of coal containing gas with natural water flow was tested compared with the non constant pressure. Results show that with the increase of moisture content, the amount of imbibition gradually increases to a stable value, but the amplitude of variation becomes smaller; the speed of imbibition is divided into three stages, including rapid increase, slow persistence, and decay to zero; the amount and rate of imbibition under the condition of constant pressure are higher than that under non constant pressure.