Based on RBF and GRNN neural network algorithm, the paper constructed RBF and GRNN neural network water demand prediction model, the model was applied to river water demand prediction, and with the basic BP neural network model and the gray GM ( 1,1) water demand prediction model fitting, prediction results were compared and analyzed. The results showed that RBF and GRNN neural network model has higher fitting, prediction accuracy, the average relative errors are within 5%. The RBF and GRNN neural network model witch is applied to water demand prediction is reasonable and feasible, the model generalization capability, high precision, stable algorithm, and BP algorithm compared with GRNN, RBF network model also has the advantages of fast convergence speed, a few tuning parameters and is easy to avoid falling into local minimum and other advantages, has a good application prospects.