Abstract: The occurrence measurement of structural plane is one of the important work of geological survey and research. In the face of inaccessible areas such as high and steep slope and unstable lithology,there are some problems in traditional measurement methods,such as poor safety and low measurement efficiency,which need to be solved by UAV and threedimensional virtualization. Unity3D platform is widely used during this years. It has been gradually applied to geological related work,but the previous research work focuses on 3D visualization,as well as the research on further applying it to 3D geological survey is relatively weak. According to the above requirements,this paper studies the 3D virtual structural attitude measurement method,and designs and develops the 3D virtual structural attitude measurement software system based on Unity3D platform. The system realizes the practical functions of 3D structural attitude measurement based on 3D real scene model,geological recording and automatic drawing of structural interpretation maps. The case study results show that the 3D virtual structure occurrence measurement system based on Unity3D is easy to develop and use. Combined with the nine point measurement method and the adjustment method of finding the mean after removing the quartile,the measurement effect is better,and the error of measurement can be effectively reduced. The measurement results are in good agreement with the traditional field attitude measurement results,and the errors are controlled within 5°,which can meet the basic requirements of engineering application. The related methods and software systems can significantly reduce the difficulty of field measurement and improve the measurement efficiency while ensuring the measurement accuracy.