Abstract: The currently developed remote fault diagnosis systems for fully mechanized mining equipment are mostly for single-machine equipment such as coal shearers, scraper conveyors and belt conveyors, and for expert remote guidance and maintenance systems based on video or virtual reality. However, there is few research on equipment group fault diagnosis systems that integrates cloud platform, remote fault diagnosis and expert remote guidance and maintenance. In order to solve the above problem, a remote fault diagnosis system of fully mechanized mining equipment group based on cloud platform is designed. Firstly, the method collects the state monitoring information of shearer, hydraulic support, scraper conveyor, transfer machine, emulsion pump station, belt conveyor and power supply system of fully mechanized working face through sensors. Secondly, the state monitoring information of fully mechanized mining equipment group is transmitted to the ground server through the underground ring network of the coal mine. The ground server performs intelligent fault diagnosis analysis, data storage, and alarm query on the received information. Finally, the state monitoring information of fully mechanized mining equipment group of the ground server is transmitted to the cloud server in a unified format through the MQTT protocol for data processing and format conversion. And the converted data is transmitted to the mobile terminal by 4G/5G network and transmitted to the PC terminal by the MQTT protocol. Therefore, the method can realize the visualization, fault query, fault alarm and timely push of fault warning information of the state monitoring of fully mechanized mining equipment group. With visual video monitoring as the medium, when the fully mechanized mining equipment fails, the video information can be transferred to the corresponding expert in real time. The expert can remotely guide the coal workers for remote maintenance through the video information. The system has been tested in the fully mechanized working face of Huangling Coal Mine in Shaanxi. The results show that the system realizes the remote fault diagnosis of fully mechanized mining equipment group. The system realizes the real-time push of the state monitoring and fault warning information of fully mechanized mining equipment group through the mobile phone platform. Moreover, the system reduces the fault rate and the number of unplanned shutdowns of fully mechanized mining equipment group and improves the production efficiency by about 30%.