As a common technical means for mine water disaster prevention, the waterproof gate can realize the isolation of the flooded area in the case of water inrush and minimize the loss. In order to realize the partition isolation of No.2 coal and No.6 coal in the second coal extension area of Dongpang Mine, it was proposed to set up waterproof gate wall. Combined with the geological production conditions of No.6 coal, the waterproof pressure was determined to be 1.8 MPa, and the inverted conical structure that could withstand large water pressure was selected. The parameters such as the length and embedding depth of the waterproof gate wall were calculated. The construction process of waterproof gate wall was put forward, including chamber construction, post-wall grouting and pressure test. The water injection pressure test showed that the total water leakage of the gate wall after 24 h was 3.1 m3 / h, which met the relevant regulations.