Abstract: In order to improve the efficiency of backfilling and guarantee the safety production of coal mine with high gas, the layout program of the special roadway which was arranged in the steady overlying strata on the top of the working face was proposed, and it was along the direction of the working face. The typical layout of the special roadway was introduced, and the principle of special roadway fully mechanized caving backfilling mining and gas extraction was discussed. Then the spatiotemporal relationship between the gas extraction and the backfilling was studied, and the benefit of the special roadway technology was analyzed. The results showed that the gob backfilling of high gas coal mine, gas extraction and fully mechanized caving mining was done in parallel by using the special roadway technology, which could significantly improve the efficiency of backfilling and release "three-unders" coal.