The computer simulation design and manufacturing needs to be a very high level of real-time and controllability, Windows operating system itself as real-time nature of the defect, brought some uncertainties to the computer simulation applications. After full argument in this paper, the author has introduced the RTX, one based on the real-time Windows simulation solutions from IntervalZero Inc. Combined with the design requirements of a particular model of CNC engraving machine, we conclude that the RTX real-time simulation applications in a Windows environment, and we write the full software CNC engraving main function modules of the program in the RTX, and this design methodology was successfully applied to a certain CNC engraving system, The actual carving examples show that the full software programs can meet the requirements of CNC engraving system in real-time based on the RTX platform.