Abstract: Aiming at the problem of large demand and high cost of traditional coal mine paste filling materials for fly ash, this paper studies the performance of paste filling materials when gangue powder replaces fly ash as auxiliary materials. Orthogonal test method and MATLAB are used to carry out linear regression prediction and 3D visualization curve model. The influence of water content and cement content on the fluidity and mechanical properties of paste filling materials is analyzed. The test results show that with the increase of cement content, the fluidity of filling slurry decreases slowly, and the compressive strength at the same age also increases slowly, and the change is obvious from 1d to 3d, and the change is small from 3d to 28d. Water content is the main factor affecting fluidity, especially the expansion degree of filling slurry. With the increase of water content, the compressive strength at the same age is significantly reduced, and the longer the age, the more obvious the result. Comprehensive analysis concluded that the optimal ratio of 15% cement content, 23% water content of filling materials, both to meet the requirements of filling strength and paste liquidity requirements.