Abstract: The tunnel construction project is a important part of a lot of traffic and hydropower construction project. It needs more prospecting and exploration data than other type construction project for information modeling of BIM design and application. However, because of many reasons, it always lacks the local prospecting and exploration data in preliminary design stage of project construction. Because of this, it's difficult to launch the BIM design and application at the beginning. And, that is also not fit of the current usual situation which are short design cycle and the requirement of providing design production in short time.As a new method,the BIM design with little prospecting and exploration could solve the problem that the geological BIM design and application are lack of adequate prospecting and exploration data in preliminary stage. It makes quick providing the trustworthy exploration and design production with little local prospecting and exploration become possible. This paper offered a BIM design of a mountain tunnel project in preliminary stage as an example in order to introduce a information modeling process of the new method which is including some way of getting geological information except local prospecting and exploration. Based on the information model of BIM,the paper provided the BIM applications of a sample tunnel section such as obtaining the rock mass classification and giving some practical geological suggestion by analysis. These presentation provided the reference to promote the further BIM design and application in preliminary stage of project construction for geological engineering. Then, the paper discussed some problem and their solution of this new method. Finally, the paper summarized that the advantages of the method are quick respond and trustworthy production, and,proposed its prospective in the design and the assistance of operating management in preliminary stage of construction project.