Blockchain-based data processing system, method and apparatus

The present specification provides a blockchain-based data processing system, method and apparatus, the system comprising: a service device for initiating, to a first blockchain network, a binding transaction for the service device and a service data contract deployed on a second blockchain network, the binding transaction being signed by a private key of the service device; service equipment which is used for initiating a processing transaction for the to-be-processed data to the second blockchain network, wherein a first node in the first block chain network is used for responding to the binding transaction and synchronizing a public key of the service equipment to the second block chain network in a cross-chain manner under the condition that signature verification of the binding transaction is passed by adopting the public key of the service equipment, and the second node in the second block chain network is used for responding to the processing transaction, and calling the servicedata contract to process