Abstract: Taking the holing through survey of Luling Coal Mine in Huaibei Mining Area as an example, based on the measurement of gyroscopic azimuth at directional edge in a certain time, regional differences wells, we testified the north-seeking stability of the gyro total station in a steady state. Through the orientation of the downhole directional edge in a certain distance, we quantify error caused by vibration of equipment by downhole carrying distance, and collect data of each gyro orientation edge and evaluate error in the north-seeking, we considered that gyro north-seeking stability is decreased with the increased of carrying distance. Based on the conclusions, we established high correlation fitting equation of the relationship about downhole gyro orientation error and carrying distance. According to this, the limitation of GT3-3 carrying distance could be concluded.