Abstract: In order to solve problems of delay information, inaccurate description and incomplete closed-loop in traditional hidden danger management system, the hidden danger investigation system framework of coal mine based on PDA was proposed. An integrated safety network office system for whole mine was established with PDA, WIFI, RFID, embedded database development and personnel position technology, etc. The system realizes real-time upload and processing of hidden danger information by wireless transmission; makes safety management transparency and visualization with image data; realizes accurate positioning of risks by the interface of personnel positioning system. The system promotes the informatization and standardization of safety management, and improves the traditional closed-loop management and achieves real-time, accurate and visual management of hidden investigation.