This study focuses on the development of a digital requirements model for novel quad-tiltrotor configuration high-speed civil rotorcraft, aiming to establish a systematic approach for turning stakeholder needs into conceptual design solutions. Based on systems engineering principals and model-based system engineering(MBSE) methodologies, this research proposes a forward design process from several specific application scenarios to ensure end-to-end traceability and traceability of requirements. A digital management framework is established to standardize the conceptual design workflow, enabling visual and standardized control over requirement validation and baseline management, which has been applied to the design of a quad-tiltrotor conceptual scheme. This framework guarantees the integrity and correctness of conceptual solutions by aligning user-driven requirements with design outputs. Furthermore, the feasibility of the proposed methodology is validated through the verification of a proof-of -concept vehicle, requirement conformance verification based on the quad-tiltrotor conceptual design scheme, and iterative refinement of the conceptual design process. This study contributes to the establishment of a centralized digital workflow for civil rotorcraft development, enhancing the efficiency and consistency of requirement-driven design activities in high-speed rotorcraft projects.