The invention provides a real-time task scheduling method oriented to the telecom-class Ethernet based on the composites-deadline-the real-time task and telecom-class Ethernet. The method comprises: scheduling in each moment, to judge system is described in a state of overload; if the system in a non-overload state, the use of the cut-off date as early as the priority tasks of EDF allocate priority, if the system is in overload state, then the value of task-based composite density, the task deadline distribution of tasks and costs to the Priority; the use of priority-based preemptive task scheduling approach to the implementation of task scheduling, to maximize the value of access to the largest systems.