Taking the coaxial pulse forming line (PFL) with cantilever structure as the research object, we carried out an optimization design for improving the vibration environmental adaptability. Firstly, through the analysis of the actual working condition and simulation calculation, the available anti-loosening measures for the blind hole screw in the inner conductor were determined as follows: using spiralock thread, applying anti-loosening glue and optimizing the number of the screws. Secondly, the insulator material was preferred to improve the connection stiffness of the inner conductor and the middle conductor according to the simulation analysis and the insulation test results. Finally, the vibration test was carried out to verify the effectiveness of the optimization design. The result show that the optimized equivalent parts of PFL could pass the long-term assessment, indicating that the vibration environment adaptability was greatly improved. The research results have reference significance for the vibration environment adaptability design of the same type of pulse power source.