There are problems of complex operation and high overall cost caused by the low level of integration of current online monitoring equipment in a ring cabinet. Thus a monitoring terminal of the ring cabinet of the internet of things (IoT) is developed, integrated with micro-power sensor access, online monitoring of mechanical characteristics and of partial discharge and standardized communication interface. The structure of the sub-module and the software architecture based on the container architecture are introduced in detail, and the realization method of data zero drift adjustment, data trigger threshold selection and feature analysis related to the online monitoring of mechanical properties is emphasized. At the same time, an improved peak retention mechanism for local discharge sampling is introduced. In order to verify performance, an experimental platform is built and some typical mechanical characteristics faults are simulated. The results show that the monitoring data are accurate and consistent, and can meet the requirements of field applications. This work is supported by the National Key Research and Development Program of China (No. 2020YFE0200400).