The work aims to select fresh fuel transportation cask design criteria, determinate the main structure of the cask, study the interface requirements and structural forms of the cask, complete the cask safety analysis, and ensure the safety of fresh fuel transportation. Based on the research of fresh fuel transportation cask design criteria, combined with regulations and user requirements, in order to ensure the safety of fresh fuel transportation under normal transportation conditions and accident conditions during transportation, the cask was equipped with multi-cushioning structures, formed aluminum and other parts that could absorb a lot of impact and vibration energy. The cask was designed with flame-retardant and heat insulation structure to ensure the safety of the contents of the cask under fire accident conditions. The appropriated loading space was designed to ensure the critical safety of the assembly, and the flexible structure was set to ensure the acceleration of the contents of the cask under routine transportation conditions. The study on fresh fuel transport cask structure was finished. The structural design rationality of the cask was indicated by analyzing cask mechanics, thermal engineering, criticality, and shielding. The transport fresh fuel is maintained subcritical. The cask design criteria is met.