Statistics show that there are 3000 ~ 4000 manhole covers per square kilometer of the city. So many manhole covers are often stolen. In addition, if the maintenance of the manhole covers is not timely, it can easily cause vehicle traffic accidents, and even the occurrence of “manhole covers eat people” incidents. They pose a serious threat to the safety of vehicles and pedestrians. In view of the above problems, this system designed the intelligent manhole cover monitoring system. This system collects the environmental data of the manhole cover in real time through the Angle inclination sensor, position sensor, water level sensor, and combustible gas sensor, respectively. STM32F103C8T6 processes the data collected by the sensors and displays the processed data on the display module. When the processed data exceeds the threshold value, the alarm module alarms. At the same time, the processed data will also be uploaded to the upper computer through the Wi-Fi module, so that the administrator can view the data remotely. After testing, the system has the characteristics of fast response speed, high collection accuracy, good stability, and so on. It provides a theoretical basis for the management of urban manhole cover and has a certain reference value.