Abstract: In alliance chain, it is usually that each node stores the content of the whole alliance chain, which is expensive. In order to reduce the storage cost of each node in the alliance chain, this paper designs a storage allocation algorithm based on consistent Hash algorithm, which can reduce the storage cost of nodes in the alliance chain while ensuring the low risk of data loss. This paper implemented a federation chain prototype to verify the algorithm. In the verification results, the proposed storage allocation algorithm has no block loss, and when the number of nodes is large, its storage cost is the lowest among the storage methods without data loss.