Through the comparison of large ancient underground engineerings found in our country with that of abroad, some questions about large ancient underground engineering were discussed, The necessity of the study was then pointed out, i. e. to find out the scientific and technological information of ancient engineerings contained in them, as will provide scientific references for the development of tourism resources and theorelical fundamentals for protection of them. The study method and some results achieved such as numerical analysis by Flac-3D and the three-dimensional modeling by 3D-MAX etc.