Abstract: In order to prevent water inrush from roof separation, a partial backfill scheme is proposed for simulation study. First of all, based on the existing data, many kinds of separation water inrush accidents occurred in China were summarized and analyzed, and the disaster model of separation water accumulation was studied deeply. Then, taking the separation water accident of 1307 working face in the first mining area of a mine in Shaanxi Province as an example, the hydrogeological conditions and the relationship between upper aquifer and separation water inrush were analyzed, and the development characteristics of roof separation space of working face were simulated by 3DEC numerical software. Finally, according to the actual situation of the mine, the technical measures to prevent water inrush from bed separation by partial backfill mining method were put forward, and the partial backfill scheme of the mine was optimized and simulated. The results showed that according to the different occurrence conditions, water inrush from roof bed separation was divided into five models. The process of separation water accumulation could be divided into initial water accumulation period, full water period and crack propagation period. When the filling rate unchanged, with the increase of strike mining width and backfill width at the same time, the supporting effect of the backfill strip on the overlying strata increased gradually, and the stress in the lower aquifer of the bed separation increased on both sides. The best scheme of partial backing is 80 m mining width and 80 m backfill width, which provides a new idea for the prevention of water inrush from roof bed separation.