Abstract: Blockchain-based charging transaction data storage does notconsider the high cost of on-chain storage, and we propose a high-efficiency chain interaction charging transaction data storage model CTDC that combines blockchain technology and interplanetary file system (IPFS). The storage on the blockchain was extended to the off-chain storage combined with IPFS, relying on the transparency and immutability of the blockchain to store only the Hash value of the corresponding amount of data. Through simulation experiments, the CTDC model only needs about 10% of the time required for the cloud storage model during the data upload phase. The time required for the data download phase is reduced by 50% compared with the cloud storage model, highlighting the model's advantages of high efficiency and low cost in charging transaction data storage.