A reusable launch vehicle is the basis for carrying out large-scale space activities and reducing the cost of space entry. It will greatly enhance the ability to enter space independently and come up with higher requirements for mission planning, demonstration, overall design, and system development of launch vehicles. Based on the model-based system engineering (MBSE) method, the forward process of model-based launch vehicle mission analysis and design is proposed first. Then, taking a launch vehicle as an example, the mission analysis and design are carried out, the mission is defined, the stakeholder requirements and mission requirements are identified, the mission application scenario is analyzed, the mission architecture is built, and the mission requirements model is established. Finally, by establishing the traceability relationship of mission requirements, the forward process of launch vehicle mission analysis is preliminarily realized, and the feasibility of the process is verified. It is of great engineering significance to improve the efficiency of launch vehicle mission analysis and system design.