The method of preserving Robinia pseudoacacia flowers for one year: 1. Choose flowers: choose healthy and complete Robinia pseudoacacia flowers to ensure that they are not damaged or withered. 2. Pruning the flower branches: Prune the flower branches, and keep the length at about 10- 15cm, so as to facilitate the subsequent processing and preservation. 3. Remove leaves and impurities: completely remove leaves and other impurities of Sophora japonica to prevent rot and mildew. 4. Drying treatment: hang the flowers upside down in a cool and ventilated place to avoid direct sunlight. It usually takes 1-2 weeks to wait for the flowers to dry completely. 5. Use desiccant: put some desiccant in a sealed container, such as silica gel or boric acid. Put the dried Sophora japonica into a container to ensure that there is enough desiccant around the flowers. 6. Sealed storage: tightly seal the container to prevent moisture from entering. Keep the container in a cool and dry place, away from sunlight and moisture.