The traditional design method of the civil aircraft brake control law has the problems that the demand analysis is incomplete, the readability is poor, and it is difficult to track the problem. This article provides a design method of civil aircraft brake control law based on MBSE (Model-Based Systems Engineering). The analysis process of the whole brake control law is divided into three levels and a total of nine steps. The aircraft brake control law was used as the research object, and all stakeholders, use cases and requirements were analyzed, and the functions of the aircraft brake control law were decomposed accordingly. Each sub-function module was also analyzed in detail. The MBSE-specific tools were used to record the analysis and iteration results of each process, and a MBSE-based civil aircraft brake control law digital design method was provided.