As the mining depth continues to increase, the pressure management of the stope and goaf is becoming more and more difficult.In order to maintain the stability of the stope,ensure the safety of the operation and prevent the collapse of the goaf,the filling method has become the preferred method for underground mining and has been widely applied.The filling method is to fill the filling body in the goaf to form a filling body with a certain compressive strength, and then carry out underground management by the supporting action of the filling body.Therefore, in the process of mining using the filling method, it is the key to efficient and safe mining of the mine to prepare the filling slurry with reasonable ratio and considerable economy to ensure that the compressive strength of the filling body can meet the needs of ground pressure management.However, there is no simple linear mapping between the filling ratio and the compressive strength of the filling body, and it is usually difficult to calculate by general mathematical methods.To this end, many researchers have conducted a lot of research on the ratio of filling slurry and the optimization of compressive strength of the filling body.Most of these studies only consider optimization under single-objective conditions, and there are few studies on multi-objective conditions.Therefore, other methods should be found to carry out multi-objective optimization research. In this paper, based on artificial neural network and genetic algorithm, a new optimization method of filling ratio is proposed.Firstly, the parameters of cement filling ratio, fly ash mass fraction and tailings mass fraction were optimized parameters, and the backfill strength was used as the optimization target to establish a BP neural network of 3-9-1.The BP neural network is optimized based on genetic algorithm, and the GA_BP neural network with higher prediction accuracy was established.Then,the GA_BP neural network with higher prediction accuracy is used as the fitness function, combined with the cost calculation function, and multi-objective optimization is performed by genetic algorithm to obtain the optimal filling slurry ratio parameter.The results show that when the compressive strength of the filling body is 1.5 MPa, the cement mass fraction is 8%, the fly ash mass fraction is 2.3%, the tailings mass fraction is 66.3%, the cost is the lowest, and the lowest cost is 29.3 yuan/t.The optimization results are consistent with the actual situation.