Abstract: Through the deformation law analysis of filling wall by existing double liquid high-water-content filling material, we improved its performance of early strength, contractility, residual strength, and put it into engineering experiment.The results show that: high-water-content filling material has high early strength after the performance improvement; the filling wall can provide enough support resistance on the roof before the basic roof's secondary fracture; the shrinkage of the material is more than 15%; it can adapt to the "rotary sink" of big roof structure; the residual strength accounted for about 85% of the initial strength to support the roof influenced by secondary mining; the high water filling material has a great effect on engineering after performance improvement.