Abstract: Mongolia is located in the central part of the central Asian orogenic belt. Based on SGG-UGM-1 gravity field model and EMAG2 magnetic field model, the spatial distribution characteristics of gravity anomalies and magnetic anomalies in Mongolia and surrounding areas are analyzed. The two-dimensional wavelet multiscale analysis of gravity and magnetic anomaly field is carried out, and the equivalent source depth of wavelet approximation and detail signal is obtained by using the method of power spectrum analysis. The results show that the gravity and magnetic anomalies in Mongolia and adjacent areas are consistent with their geological structures, which reflects the arc-shaped structural characteristics of Mongolia. Besides, the wavelet decomposition results of gravity and magnetic anomalies reveal that the fault zone anomalies are probably caused by the change of the intensity and magnetic of the deep material of crust and mantle when the material wells up along the fractures.