Intelligent security system is an important part of intelligent site construction, which directly affects the life safety of operators and the level of engineering supervision. Traditional security communication systems for construction, mineral mining and other fields have problems such as small network coverage, low capacity, short terminal life and relatively simple function. According to the application scenarios and business requirements of intelligent security system, this paper uses LoRa AD-hoc networking technology to carry out the network architecture research and key technology design of intelligent security AD-hoc networking system. Further, the detailed design of the embedded software of the system terminal and gateway is completed, and the functions of physical sign monitoring, danger warning and terminal positioning are realized.