Abstract: The paper analyzed research status of digital mine with background of ongoing demonstration digital mine construction and completed digital mine planning and research of Shenhua Group, and pointed out that the digital mine was a typical multi-level network system, but research of security was lacking. It summarized seven aspects of particularity of the digital mine security issues including vulnerable, existing a large number of hierarchical heterogeneous complex system and so on. It presented a multi-level real-time security framework for digital mine, which uses a combination of isolation and monitoring mechanisms, and it provides a new guideline to solve the problems of digital mine security.