Abstract: Viscosity is an important parameter of slurry liquidity and workability.For getting the viscosity change rule of high density filling slurry with waste rock-tailings under the condition of multi-factor, make rheological experiment, and obtain the rheological parameters.Response surface method is used to analyze the influence of fine fraction content on viscosity.The results show that the change of viscosity is basically consistent with the multi-factor coupling, and fine fraction content had great influences on the viscosity, mass concentration came second; when solid phase concentration increases, the viscosity of the slurry increases; viscosity decreases with the increase of fine particle level, and the viscosity reaches the minimum when the fine grain level reaches a certain range, and fine-grained content continues to increase, the viscosity too.On the premise of meeting high concentration, the fine content in slurry should be controlled in 30%-34%, and mass concentration should be less than 84%.