A computer-implemented method includes: compressing, by a service party, target data to be stored according to a preset compression template; assembling the compressed target data and a unique identifier of the preset compression template into storage transaction data; and transmitting the storage transaction data to a node device on a blockchain, so that the node device, in response to the storage transaction data, searches for a smart contract published on the blockchain, in which the smart contract corresponds to the unique identifier, invokes the preset compression template to determine that a data format of the target data conforms to a data format specified by the preset compression template, and in response to determining that the data format of the target data conforms to the data format specified by the preset compression template, stores the compressed target data.