This disclosure relates to blockchain-based transaction processing. In one aspect, a method includes obtaining pieces of transaction data. At least a portion of the pieces of transaction data have a respective group identifier that identifies a node group for the piece of transaction data. Each node group includes multiple blockchain nodes. Pieces of transaction data that have a same first group identifier that identifies a first node group are identified in the obtained pieces of transaction data. The pieces of transaction data are packaged into a first packaging result based on the pieces of transaction data having the same first group identifier. The first packaging result is submitted to a blockchain for storage.