Abstract: There are many communication nodes, long communication distance and complex electromagnetic environment in fully mechanized working face. The existing communication system of hydraulic support electro-hydraulic controller generally lacks fault diagnosis function. In order to solve this problem, a set of communication system of hydraulic support electro-hydraulic controller with fault diagnosis and fault location function is designed by taking the ZDYZ−JK type hydraulic support electro-hydraulic controller as the research object. The system has a two-way communication network. One way adopts a bus structure to connect the main controller and all the support controllers at the same time. The other way adopts a serial structure to only connect two adjacent support controllers. The communication between the main controller and the support controller adopts a bus mode. And the communication and control between adjacent support of the support controllers under the manual mode adopts a serial mode. Therefore, the two modes do not interfere with each other. After receiving the communication signal of the main controller, the support controllers can perform fault diagnosis and record fault conditions in real time. At the same time, the support controllers can periodically send diagnosis information to the support controllers on adjacent supports. Therefore, the diagnosis result of the support controller with bus communication fault can be fed back to the main controller through the support controllers on the adjacent supports. Therefore, when the function of sending a message by the support controller fails or an error occurs, the error can be reported in time. And the report content includes the controller number information to realize the fault location. The experiment results show the following two points. ① The system works well with 121 communication nodes and the maximum communication distance of 1 040 m. And the number of nodes can be increased to 255, which meets the design requirements of 200 nodes and 1 000 m communication distance. ② The system can diagnose and accurately locate various communication faults caused by electromagnetic interference of working face, physical damage of electro-hydraulic controller, software error of electro-hydraulic controller and so on.