In the aerospace electronics field, time-triggered ethernet (TTE) can act as an integrated network for carrying control commands and real-time data, with time-triggered (TT) communications for missions with high critical levels. TT communication task scheduling requires deepening design parameters such as topology configuration and path selection; however, in the early stage of design, it pays more attention to the application layer requirements for communication tasks, and it is necessary to plan TT communication tasks without deepening design parameters. This paper proposes a two-stage communication task planning method. Firstly, the communication task switching matrix is expanded into a communication task capacity matrix. Then, the BVN decomposition method is introduced and improved, and the latter is decomposed into time slices of non-conflicting communication task combinations, which is easy to form. A template that is arranged during subsequent scheduling. Case study shows that the planning method can reduce the communication task delay by 43% and compatible with the subsequent time schedule generation step.