In the process of sharing accounting information using cloud computing technology, the integrity of the data is related to the security of the transmission and utilization of accounting information. For this reason, this paper studies the algorithm optimization based on the multi-branch path tree LBT. Multi-branch path tree LBT adopts distributed data storage method to reduce the number of hash operations. The data integrity auditing scheme is designed for different phases of cloud auditing, and the dynamic update process of cloud data is optimized to improve the data integrity verification effect. This algorithm can still maintain a high challenge success rate after more than 300 challenge data blocks, and the total overhead of the experimental computation does not exceed 8 ms, and the verification efficiency is also better than the comparison algorithm. Therefore, the research idea of this paper has validity and has improved effect on data integrity verification in the process of cloud computing smart accounting informatization.