Abstract: IAn online temperature monitoring App for electrical equipment operation is design, which adopts a client-server mode. The client terminal is developed using H Builder X, and the server is built using the Baota Linux panel platform. The monitoring device transmits temperature data to the server through 4G communication protocol, processes it, and stores it in the database. The designed App enables data visualization for clients and is available to send alarm information in a timely manner, which improves the safety and reliability of device operation.