Abstract: In order to master the influence range and intensity of minging to the two-gates of Tingnan coal mine, to evaluate the reliability of the support in advance, based on the work pressure monitoring analysis of the support in advance and the observation and analysis of the deformation of the two channels, this paper get the influence range of the 302working face to the two-gates is 25 meters, and the working face has a larger influence to the two-gates within 10 meters, and the overall deformation of the roadway is relatively small. Finally confirmed that the support in advance of Tingnan 302 fully-mechanized working face is reasonable and reliable.