Abstract: Computer interlocking software is one kind of safety critical application. With the continuous expansion of its functionalities, its development and maintenance will face ever-increasing pressures. Therefore, a study was made on the SCADE, namely Safety Critical Application Development Environment, and the process of software development that the SCADE can support. According to the requirements formulated in related technical specifications, a trial was made to use the SCADE to develop computer interlocking software. The practice demonstrates that the SCADE is a suite of tool applicable for model-based software engineering and can enable V-model software development process and helps the developers effectively manage the risks associated with software development. It provides a reference for the development of interlocking software.