Abstract: In order to improve the radio wave detection accuracy of coal mine underground working face and reduce the problem of large error and low accuracy of single frequency electromagnetic wave detection results. Through the analysis electrical parameters of coal and rock, it is believed that coal is affected by factors such as coal-forming conditions, geological structure and buried depth, and the electric field strength will vary when the loaded charge inside coal passes through different spatial structures and crack sizes. Under the disturbance of radio waves, charged particles originally in equilibrium state show electrical characteristics through polarization movement, samples of typical coal in different areas are taken to analyze its microstructure and internal pores. The interaction between electromagnetic waves of different frequencies and the coal sample’s own dielectric constant, conductivity, dissipation coefficient, incident angle and amplitude attenuation constant and other related factors are studied, and the experiment is carried out at 5 frequencies including 1 kHz, 10 kHz, 100 kHz, 1 MHz and 8 MHz, and it is found that the change rule is all at 1MHz. The dielectric constant and conductivity decrease first and then increase, and the amplitude attenuation constant is positively correlated with the incidence angle and conductivity, and negatively correlated with the relative dielectric constant. The research results are applied to the geological structure exploration of 33170 working face of a mine in Yulin Area, Shaanxi Province. By setting 0.158 MHz and 0.365 MHz radio waves of high and low frequencies for transmission, relatively consistent abnormal areas appear in the upper and lower lanes of the working face, but there are obvious differences in the field intensity attenuation intensity reflected by radio waves of different frequencies in the same area. The multi-frequency detection means are used to achieve accurate exploration of abnormal areas inside the working face. The conclusion is basically consistent with the comprehensive analysis of geological conditions, which effectively improves the accuracy and reliability of radio wave.