Based on civil aircraft operation scenario and airworthiness regulations, a requirement-oriented forward design method for civil aircraft system was proposed. Taking the accumulator brake of aircraft wheel brake system as an example, the needs of stakeholders was analyzed to define the requirements of accumulator brake system, then the process of accumulator brake was analyzed and calculated. The general simulation software of accumulator brake system was established based on MATLAB/Apps platform, and the requirements of accumulator brake were validated based on model. Finally, a multidisciplinary integrated model of wheel brake system was established based on Simscape and Simulink platform for the collaborative simulation of the accumulator brake system, and the requirements of accumulator brake were verified based on model. By using the forward design method constructed based on requirement, the requirements definition is completed in the preliminary design phase，the validation and verification of requirement is completed through the model, reducing the risk of system development.