In recent years, the tasks of airborne avionics system have been more and more diversified, a single display is unable to meet the mission requirements, and the integrated multi-display Cockpit Display System (CDS) has become a trend. In this case, it is particularly important whether the multiple monitors can respond to the operation correctly, and can display the information accurately. According to ARINC661 specification, a multi-display picture processing method based on the layer and session mechanism was implemented. We studied the operating mechanism of ARINC661 based CDS, confirmed the interaction mode between the User Application (UA) and CDS, explored the layer logic and the event processing mechanism of multi-display picture.A session mechanism between the layers and each display was established through UA, and finally the processing of the display picture was realized, through which the crew could obtain correct information of relevant tasks. The simulation result shows that the design is reasonable and the operation is reliable.