In hybrid real-time systems, schedulers must guarantee that all of hard real-time jobs are finished by their deadlines and the QoS of soft real-time tasks and non real-time tasks are improved as greatly as possible. This paper presents RPDS (rigorously proportional dispatching server) algorithm, and constructs a hierarchical scheduling framework based on that. RPDS partitions CPU time flow into continuous segments, and in each segment RPDS will forcibly assign one time slice to non-hard real-time tasks. Experimental results show that RPDS can allocate processor time to various application classes reasonably and reduce the deadline miss ratio of real-time tasks effectively.