Gyro orientation technique is widely used in many fields, such as navigation, aviation, space probe and engineering construction. It is one of the key techniques in subterranean construction. In this paper, the advantages and disadvantages of the orientation methods such as GPS orientation, gyro-orientation and astronomical orientation are discussed. The astronomical azimuth measurement system that is aided by an automatic gyro station is introduced. This system is composed of an automatic target recognition station, a gyro orientation device, a GPS receiver and a portable computer. By used of the system, surveyors could survey the astronomical azimuth at any time and in any field accurately whether on ground or underground. Test show that the measurement precision could meet the demand of fist order for the astronomical azimuth. Other gyro-theodolites could be compared with this system, and thus be corrected. The automatic target recognition station is the key instrument in the system and the automatic target recognition technique (ATR) is taking an important role in the precise orientation measurement. We made a test to analyze the aiming errors difference between a long distance and a short distance target by the ATR and precise manual aiming. The result shows that there are some differences for different distances by the ATR. When using the gyro station for an orientation we should choose different observation method.