Abstract: For avionics hard-time network, a composited wavelength division multiplexing (WDM) structure based on broadcasting network and wavelength routing network and scheduling structure model were proposed. For the hard real-time messages in the multichannel networks, a load ratio round-robin schedule method was proposed which allocating weight based on message load ratio in multichannel. Analysis of the differences between the interior messages and the exterior messages in the subsystem were given. Then the hard real-time schedulability conditions which the interior messages scheduled for one time and the interior messages scheduled for many times were derived to satisfy hard real-time communication of all of the messages in the avionics system. The key parameters were designed and optimized from the system resource usability and stability aspect for the real avionics system. Finally, a practice example was given.