A method and an apparatus for creating an index in a blockchain-type ledger, and a device are disclosed. According to solutions provided in implementations of the present specification, a service attribute of a data record written to a ledger and a storage location and a sequence number of the data record in the ledger are determined, a mapping relationship is established between the service attribute, the storage location, and the sequence number, and an inverted index with the service attribute as a primary key is created, facilitating subsequent query.