A blockchain-based transaction processing method, applied to a client device, wherein a Nonce list corresponding to a user account is maintained in a blockchain, the Nonce list comprises a plurality of Nonce records, the Nonce record comprises a group identifier and a Nonce value, and the method comprises: in response to an initialization instruction for the client device, obtaining the Nonce list maintained in the blockchain, and maintaining the obtained Nonce list on the client device; obtaining, from the Nonce list maintained on the client device, available Nonce records that comprise the same group identifier for each of a plurality of transaction groups, wherein each transaction group comprises a plurality of transactions that need to be concurrently executed and are initiated by a user through the user account, wherein the plurality of transaction groups need to be executed in a specific order determined by the client device, wherein the group identifiers of the plurality of transaction groups indicate the execution order of the plurality of transaction groups, and wherein the Nonce records in the Nonce list maintained on the client device are marked as available by default; marking the available Nonce records as unavailable in the Nonce list after obtaining, from the Nonce list maintained on the client device, the available Nonce records that comprise the same group identifier for the plurality of transactions that need to be concurrently executed and are initiated by the user through the user account; respectively adding the obtained available Nonce records to the plurality of transactions; publishing the plurality of transactions in the blockchain, so that a node device in the blockchain matches an available Nonce record in a transaction published by the client device with the Nonce record in the Nonce list, and when the available Nonce record matches any target Nonce record in the Nonce list, processes the transaction, and concurrently executes a plurality of transactions with the same group identifier in processed transactions; determining whether a notification message indicating that the transaction is processed is received from the node device; and if yes, monotonically increasing a Nonce value in the available Nonce record based on predetermined amplitude, and re-marking the available Nonce record as available in the Nonce list after monotonically increasing the Nonce value. in response to an initialization instruction for the client device, obtaining the Nonce list maintained in the blockchain, and maintaining the obtained Nonce list on the client device; obtaining, from the Nonce list maintained on the client device, available Nonce records that comprise the same group identifier for each of a plurality of transaction groups, wherein each transaction group comprises a plurality of transactions that need to be concurrently executed and are initiated by a user through the user account, wherein the plurality of transaction groups need to be executed in a specific order determined by the client device, wherein the group identifiers of the plurality of transaction groups indicate the execution order of the plurality of transaction groups, and wherein the Nonce records in the Nonce list maintained on the client device are marked as available by default; marking the available Nonce records as unavailable in the Nonce list after obtaining, from the Nonce list maintained on the client device, the available Nonce records that comprise the same group identifier for the plurality of transactions that need to be concurrently executed and are initiated by the user through the user account; respectively adding the obtained available Nonce records to the plurality of transactions; publishing the plurality of transactions in the blockchain, so that a node device in the blockchain matches an available Nonce record in a transaction published by the client device with the Nonce record in the Nonce list, and when the available Nonce record matches any target Nonce record in the Nonce list, processes the transaction, and concurrently executes a plurality of transactions with the same group identifier in processed transactions; determining whether a notification message indicating that the transaction is processed is received from the node device; and if yes, monotonically increasing a Nonce value in the available Nonce record based on predetermined amplitude, and re-marking the available Nonce record as available in the Nonce list after monotonically increasing the Nonce value.