The work aims to explore the functional design optimization and shape upgrade of unmanned delivery vehicles based on the application research of modular design for unmanned delivery vehicles, to improve their flexibility and scalability and adapt them to different scenarios and needs. Through modular theoretical analysis and functional analysis of unmanned delivery vehicle application scenarios and technical structures, the entire vehicle system was divided into basic modules, modified modules, and additional modules. The functional modules were replaced as needed to cover a wider range of unmanned delivery fields, in order to address the multi-scenario nature of delivery. The effectiveness of the modular design method for unmanned delivery vehicles was validated based on functional configuration through the practical application of team unmanned delivery vehicle design. The modular design achieved the "one vehicle with multiple functions" of unmanned delivery vehicles, allowing for quick assembly and disassembly, facilitating maintenance and upgrading, while reducing unnecessary assembly and debugging time, improving work efficiency, and enhancing the ability to quickly respond to market changes and user needs. Through modular functional design research and multi-scenario design practice, the performance and reliability of modular design for unmanned delivery vehicles have been demonstrated, meeting user needs and diversifying product structures to adapt to increasingly complex usage environments.