In order to solve the problem that embedded real-time systems' miss rate of real-time task is too high and the problem of poor stability of real-time scheduling while the load of the system is uncertain, a scheduling model based on feedback control was proposed. This model consisted of an improved multi-level queue scheduler and three controllers, those were access controller, execution level controller and Proportional-Integral-Derivative (PID) controller. The deviation of task miss rate was feedbacked to the PID controller and generated a corresponding adjustment, the adjustment acted on the other two controllers to adjust the level of real-time tasks. Tasks adjusted were executed by the scheduler. After structural adjustment and improvement, the scheduling model was applied in embedded Configurable operating system (eCos). The experimental results show that the proposed method can reduce miss rate of tasks, and solve the overload problem of the system.