The directional drilling technology with MWD system used in underground is one of the important means for exploration of hidden geological factors causing disasters in coal mine. Compared with the conventional drilling technology, directional drilling technology has the advantages of precise trajectory control, broad branches coverage, calculation of coordinates and some others. In order to test the accuracy of the measurement results of the new MWD system, a field experiment was carried out in the well and 2 testing holes were drilled. The results show that the accuracy of new MWD system is excellent, the real drilling deviation can be kept in the allowable range of 5‰ of the borehole depth and can provide accurate three-dimensional coordinate parameters to meet the requirements of accurate exploration of hidden geological factors causing disasters in coal mine.