Abstract: This paper gives detailed explanation as to the essentials and characteristics of digital tunnel and the reality of digital tunnel technology. Based on unified coding rule and multi-source data processing technology, digital tunnel technology is intended to realize digitization of the engineering data during survey, design, construction, operation and maintenance, build the digital tunnel model, seamlessly integrate the data of the 3 stages including design, construction and operation & maintenance, and establish the business management mode based on data and models.Based on digitization of engineering data, borne by models and through the means of parametric modeling and data inversion, this technology adequately reveals the interconnection between various engineering data, in order to guide the design, construction and maintenance decisions regarding tunnel and comprehensive application of data, render accurate data for construction, operation and management of tunnel projects, provide efficient comprehensive information analysis service, and achieve mutual exchange of information in the whole life cycle