As our country gradually enters the age of aging, in view of the problems of high cost, complicated operation and insufficient humanization in the traditional interaction mode of the Internet of Things system, this paper designs an intelligent security inspection system for the elderly living alone based on the Internet of Things. The system consists of OneNET cloud platform, AIR208S module and STM32 lower computer module, and realizes two-way communication between STM32 lower computer and OneNET upper computer through MQTT protocol. The STM32 lower computer system in this paper consists of a data acquisition module, a heart rate monitoring module, a GPS positioning module, an intelligent alarm module, a central control module and a data communication module to form a closed-loop control system. Through the actual test, the system can realize real-time positioning, indoor temperature and humidity collection, real-time monitoring of heart rate and blood oxygen saturation, automatic detection of smoke and gas leakage, intelligent alarm and control of smart home equipment and other functions. In order to "guard" the health and safety of the elderly living alone, a full-cycle intelligent intelligent security inspection method is provided, which can effectively ensure the life safety of the elderly living alone and alleviate the pension problems of the elderly living alone.