This paper provides a solution of physiological data collection and early warning system for the elderly living alone based on Internet of Things technology. The system adopts STC15F2K60S2 chip microcomputer, various sensors, display screen, buzzer and other hardware for system development. The system realizes the real-time collection and display of human physiological data such as blood pressure, heart rate, step counting, body temperature, indoor temperature and humidity information. When the data of blood pressure, heart rate and temperature exceeded the preset value, the server would warn with flashing lights and buzzers. The system experimented the functions of information acquisition, display and early warning of mobile phone and PC. In addition, the server can synthesize data collected over a period of time to predict the value of future data. The system can be used for the nursing of the elderly living alone or the monitoring and management of the special population in the community by community workers, effectively preventing the physiological accidents and psychological hidden dangers of the elderly and those with mobility difficulties.