Different from the commercial applications, the avionic wavelength division multiplexing (WDM) network lays much emphasis on hard real-time characteristics. The real-time scheduling algorithm is a key issue to ensure the message transmission performance. According to the real-time communication requirement of avionic WDM network and the traffic characteristics of the avionic network, a weighted round robin scheduling algorithm is proposed based on the periodic task model of real-time communication to guarantee hard real-time transmission in an airborne WDM network, which is comprised of the rotation cycle selection, weights assignment scheme and multi-channel allocation method. Among them, multi-channel allocation method efficiently reduces the splitting times of the message; combined with examples, message weights assignment scheme is determined and it is pointed out that the optimal rotation cycle cannot guarantee the minimum message delay ratio. Research results are meaningful for the design of real-time scheduling parameters and the current practice of avionic WDM network.