Abstract: In order to solve the technical limitations that the signal transmission of MWD system must rely on special communication cable pipe instead of the conventional drill pipe in coalmine, mud pulse wireless transmission technology is put forward. Based on the research of engineering parameter measurement techniques, mud pulse carrier signal transmission, intermittent operation mode design and control, aperture signal reception and demodulation processing, YHD3-1500 mine mud pulse wireless MWD device is developed. According to the field test in Sihe and Chengzhuang coalmines, the technology is feasible and the device can improve the strength of drilling pipe and the applicability of directional drilling technology with high signal amplitude, long transmission distance, long working hours, and high stability, which can meet the need of directional drilling in coal mines. The test results show that the mud pulse wireless MWD device has the characteristics of large signal amplitude, high working stability, long transmission distance and working time. The device is not limited by the drill pipe during operation, which can not only improve the depth of drilling hole, but also realize real-time control of borehole trajectory, broadening the application field of directional drilling.