Abstract:Based on the massive long-term observation data from existing geomagnetic stations, this paper disregards the formation of geomagnetic field and the complex mechanisms of many influencing factors, and analyzes the temporal and spatial correlation of the variable geomagnetic field, mining the regular information contained in the data. It further constructs the prediction model of geomagnetic field based on the BP neural network. The forecasting data of the established model is validated by the observation data of geomagnetic stations, and the result shows that root mean squared error of the 100 arbitrarily chosen validation data is 4.8 nT, and this solution accuracy can meet the need of general scientific research.