A method and an apparatus for creating an index in a blockchain-type ledger, and a device are disclosed. According to one implementation, a method may include obtaining, by a centralized database server, a data record, wherein the data record is stored in a blockchain-type ledger, and wherein the data record comprises a service attribute and a sequence number; determining location information of the data record in the blockchain-type ledger, wherein the location information comprises a block height of a data block comprising the data record, and an offset of the data record in the data block; establishing a mapping relationship between the service attribute, the location information, and the sequence number; and based on the sequence number, writing the mapping relationship to an index.