Methods, systems, and apparatus, including computer programs encoded on computer storage media, for blockchain-based notification are provided. One of the methods includes: obtaining information in a block of a blockchain to determine a current state of a workflow, wherein a blockchain contract deployed in the blockchain is executable to update the current state among one or more states of the workflow; updating a locally-maintained state machine based on the determined current state; and in response to determining that the updated state machine corresponds to one of the one or more states, transmitting a notification message to one or more subscribers subscribing to the one state.