The artificial neural network (ANN) prediction model based on BP neural network is built to predict the weighing efficiency of rotor weighing machine which is difficult to carry out by ordinary mathematical methods. The key factors of the weighing efficiency are found by analysis of the input layers. The prediction accuracy of the weighing efficiency of the model is studied under 5 kinds of input layer factors, and the simulation analysis is carried out. The results show that the model can effectively predict the weighing efficiency of the rotary weighing method, and the prediction accuracy is high.