Abstract: For the further verification of measurement accuracy of directional hole, the field experiment on directional drilling through roadway was carried out. The results show that measurement while drilling system has high measurement precision, and up-down deviation is not more than 2‰, and maximal value of left-right deviation is 5.4‰. According to the exact drilling experiment and application, accurate hole designing and strict trajectory controlling should be carried out to achieve accurate target hitting. For high measurement precision of up-down deviation, up-down deviation is the main reference; meanwhile, we should pay attention to error range of left-right deviation.