Abstract: With the development of blockchain technology, the blocks in blockchain are keeping increasing, the new blockchain nodes are facing the problems of increasingly large storage and increasingly long time in block synchronization. In order to solve the problems, this paper proposes a blockchain node storage optimization scheme, which firstly calculates the number of blocks in each sharding by analyzing the probability of blockchain malicious nodes, then obtains the number of blockchain nodes and the probability of the block with the largest number being attacked by malicious node within the sharding, and at last, calculates the number of copies that need to be stored in each sharding. Experimental analysis shows that the optimization scheme reduces 50% blocks storage and 22% synchronization time in blockchain nodes, therefore, it can not only reduce the node storage in blockchain, but also improve the efficiency of new nodes joining the blockchain.

Key words: blockchain, storage optimization, sharding block, copy strategy