The invention provides a transaction-based blockchain consensus mechanism, which comprises the following steps: counting transaction data in first X blocks of a current block, sorting the transactiondata according to the transaction data, and selecting corresponding first Y nodes according to a sorting result, the transaction data comprising a transaction quantity and / or a transaction amount; enabling the first Y nodes to perform computing power competition according to the target value, calculate a result value, obtain a verified node as a winning node according to the result value, and obtain the accounting right of the new block; and enabling the winning node to package the newly generated transaction data into the new block and obtains currency rewards. Compared with an existing PoW mechanism and an existing PoS mechanism, the node selected by the mechanism is high in activeness in the block chain network, the willingness of maintaining the block chain network is high, waste of computing power can be effectively reduced, excessive centralization is avoided, and resource consumption is reduced.