Along with the continuing increase of network bandwidth, the time gaps between the arrived packets are decreasing. The changed situations demand the core router to improve the ability of packet processing. The traditional packet scheduling algorithms, such as WFQ, are difficult to implement in high performance core router because of the problems of performance and extensibility. The paper proposes a new un-precise packet scheduling scheme, which improves the performance of the scheduler by modifying the classical packet scheduling algorithms to simplify the design of hardware. The scheme doesn't affect the QoS quality of the algorithms. The delay performance of this scheme is analyzed and computer simulation results show that the delay performance of SLQF is consistent with that of LFQ on the whole.