RM algorithm is a classic fixed priority real-time scheduling algorithm,but in most embedded real-time systems,where the workload is composed of many tasks of high frequency and short execution time,the overheads from context-switches of real-time operating system will lead to a low resource utilization rate if RM algorithm is directly used.By studying the preemption relationship of the tasks scheduled by RM algorithm,a model of context-switches overheads is established with task attributes,based on which the run-time context-switches overheads of RM algorithm are reduced by optimizing the release time of the tasks in embedded real-time systems.Finally,the experimental results show the validity of the proposed strategy.