Aiming at the deficiency of the contact health detection devices, this paper proposes a new health detection system based on millimeter wave radar, which combines noncontact and contact mechanism. In addition to collecting vital signs such as human breathing and heartbeat, the system also collects key information such as human movement, blood oxygen and body temperature through deploying various IoT (Internet of Things) node devices. Specific implementation is based on 4G/WIFI/Bluetooth communication modules by using MQTT protocol to remotely transmit the collected data to the IoT platform and client APPs. Furthermore, the cloud platform stores and analyzes the data, ensures the stability of data storage, and draws real-time curves to make the physical condition of the test subject more intuitive. Experimental results have proven that the presented system has good stability, wide application range and high application prospect, especially for the life monitoring of the elderly living alone.