In the ARINC661 specification,there is a large amount of data interaction between UA and CDS with short transmission period, and it is difficult to comprehensively and meticulously analyze the instructions in real-time monitoring process.To solve the problems, we studied the offline detection technology of the cockpit display system, and designed such methods as ring data batch storage,simulation UA, and anomaly positioning, which can reproduce the instruction interaction process in an offline environment.The test results showed that the design is reasonable,reliable, and can detect interactive commands in an offline environment.