A block data access method, applied to a blockchain node, a storage space corresponding to the blockchain node including a local storage space and an external storage space, the external storage space including at least one of a cloud storage server or a distributed storage device, the local storage space being used to store one or more blocks with an access value greater than a value threshold, the external storage space being used to store one or more blocks not stored in the local storage space or to store a complete set of all blocks, and an access value of any block being positively correlated with a service value of a transaction included in the any block, a block height of the any block, and an access value of an associated block of the any block, wherein a degree of impact of the access value of the associated block on the access value of the any block is negatively correlated with a block height difference between the associated block and the any block; the method comprising: determining, according to a block index table corresponding to the complete set of all blocks, the local storage space or the external storage space as a target storage space including a target block; or determining whether relevant information of the target block is recorded in a block index table of the one or more blocks stored in the local storage space; if yes, determining the local storage space as the target storage space; otherwise, determining the external storage space as the target storage space; and accessing, from the target storage space, target data included in the target block, wherein two blocks are mutually associated when at least one transaction included in one block and at least one transaction included in the other block are mutually associated transactions, and wherein two transactions are mutually associated when a same asset type is involved, a same or similar transaction type is involved, a same user is involved, or involved users are associated. a storage space corresponding to the blockchain node including a local storage space and an external storage space, the external storage space including at least one of a cloud storage server or a distributed storage device, the local storage space being used to store one or more blocks with an access value greater than a value threshold, the external storage space being used to store one or more blocks not stored in the local storage space or to store a complete set of all blocks, and an access value of any block being positively correlated with a service value of a transaction included in the any block, a block height of the any block, and an access value of an associated block of the any block, wherein a degree of impact of the access value of the associated block on the access value of the any block is negatively correlated with a block height difference between the associated block and the any block; the method comprising: determining, according to a block index table corresponding to the complete set of all blocks, the local storage space or the external storage space as a target storage space including a target block; or determining whether relevant information of the target block is recorded in a block index table of the one or more blocks stored in the local storage space; if yes, determining the local storage space as the target storage space; otherwise, determining the external storage space as the target storage space; and accessing, from the target storage space, target data included in the target block, wherein two blocks are mutually associated when at least one transaction included in one block and at least one transaction included in the other block are mutually associated transactions, and wherein two transactions are mutually associated when a same asset type is involved, a same or similar transaction type is involved, a same user is involved, or involved users are associated. determining, according to a block index table corresponding to the complete set of all blocks, the local storage space or the external storage space as a target storage space including a target block; or determining whether relevant information of the target block is recorded in a block index table of the one or more blocks stored in the local storage space; if yes, determining the local storage space as the target storage space; otherwise, determining the external storage space as the target storage space; and accessing, from the target storage space, target data included in the target block, wherein two blocks are mutually associated when at least one transaction included in one block and at least one transaction included in the other block are mutually associated transactions, and wherein two transactions are mutually associated when a same asset type is involved, a same or similar transaction type is involved, a same user is involved, or involved users are associated.