In satellite communication links, serial communication faults often involve multiple devices. If the fault point cannot be accurately located, it will affect the execution of communication tasks. In order to quickly locate the serial communication problem, based on the study of serial communication mode and communication protocol, appropriate hardware modules is selected, corresponding control software is designed, a serial detection platform is built, the channel equipment with the detection platform is connected and tested, the functions of performance evaluation and serial state diagnosis of the equipment under test are realized, which provides support for quickly handling equipment problems and improving equipment maintenance efficiency.