Disclosed are an IoT system and a monitoring method for monitoring association between indoor environment and health of elderly people. Such IoT system comprises an environmental and health parameter monitoring system and an IoT data association platform, the monitoring system performs data transmission with the IoT data association platform by a GPRS wireless communication module and a data receiving API interface. The monitoring system is combined with the IoT data association platform. The IoT system has a small physical volume and can be fixed to the periphery of the human body by wearing. The constructed IoT environment and health association data platform can remotely and online monitor change of the temperature and humidity and particle concentration in the environment where elderly people are located, and remotely and online monitor the blood pressure and heart rate of elderly people. The health risks can be predicted in real time by input environmental data.
