The development of largescale civil aircraft is a complex system engineering of multisystem and multidisciplinary crosslinking. The main manufacturer of civil aircraft should implement requirements validation and verify work in the early design process to find out the defects, reduce the cost of subsequent iterations of design, shorten the design cycle and improve the competitiveness of the product. In this paper, we introduce the scenariobased testing method in software engineering field by using scenario as a tool. Taking the aircraft triggering TAWS mode 1 warning during approach as an example, we used SysML activity diagram to construct the civil aircraft operation scenario model and generate test cases. Introduce the test case importance to rank the test cases for guiding the subsequent testing work, which can provide support for realizing the scenariobased requirement validation and verification.