Abstract: The reflective spectral values of the major geologic bodies in Helanshan District were measured, the TM false color images were interpreted and a field investigation was made. Then the interpretation keys of thrust system on the TM images were set up. As a result of above the author considers that in the study area occurs a the range of the duplex isn’t less than 8000 km², and the thrusted distance is more than 50 km. This new conclusion will be of great geologic significance for the exploration of coal fields.