Abstract: To achieve construction of fine tailings dam by upstream method, the problems of low shear strength and consolidation draining difficulty need to be solved. United application of earthwork synthetic materials as 3D solid water seepage system of tailings dam is put forward. By establishing 2D finite element model for seepage calculation of a tailing reservoir, the seepage fields are compared in different schemes, and reasonableness and effectiveness of the water seepage method are obtained. The results show that the application of horizontal geomat and vertical plastic blind drain water seepage technology can effectively reduce the saturation line of tailings dam, and the maximum amplitude reduction reaches 230.43%. The water seepage system can significantly decrease the gradient of permeation, reducing the possibility of seepage failure.