Abstract: With the application and development of filling mining method,the application of cemented ungraded tailings filling in metal mines is increasingly wide.Taking a mine as the research background,according to the production scale and actual production situation of the mine,the filling slurry with a concentration of 62 % and cement-sand ratio of 1∶4 is selected.The flow characteristics of cemented ungraded tailings filling slurry is numerically simulated with FLUENT software,and the physical parameters of cemented ungraded tailings filling are determined,and a suitable numerical model is constructed.Through numerical simulation and theoretical calculation,the two are compared and the final results are analyzed.The results show that the inlet velocity is related to flow velocity of the core flow zone and the flow velocity decrease to the tube wall,and the greater the inlet velocity is,the greater the flow velocity is,the greater the velocity of the flow velocity decreases from the center point of the pipe to the tube wall; when the inlet flow velocity is set,the smaller the pipe diameter is,the greater the pressure drop of the unit distance is; after the curvature radius,the maximum velocity in the elbow increases,and the larger the bending radius,the smaller the maximum velocity in the elbow.