Abstract: The resistivity curves of TE and TM polarization modes of audio magnetotelluric method (AMT) have respective characteristics under different static effects. Theoretical forward modelling results show that TM polarization model is relatively strong influenced by topography, while TE polarization model is weakly affected, which is more advantageous in identifying mountain structures. In the practical application, it is found that TE polarization mode is in good agreement with the drilling data by comparing the inversion results of two polarization modes in the same cross-section, which is very clear and effective in identifying the low resistivity anomalies of water-rich areas in mountain tectonic belt.