Through analysis of the TSR ( Terminate and Stay Resident), the principle to achieve the real time multitask system on DOS ( Disk Operating System) work station in enterprise management information system and the key technique in achieving multitask are discussed. 通过对TSR(驻留程序)的分析,讨论了企业管理信息系统中DOS磁盘操作系统工作站上实现实时多任务系统的原理及具体实现时的关键技术。