The invention discloses a public key arbitration quantum signature protocol based on quantum block encryption, which belongs to the technical field of quantum secret communication and comprises quantum key sharing among a signer, a receiver and arbitration through quantum key distribution. The signer prepares two parts of sub-messages and one part of sub-signature, sends one part of sub-message tothe receiver and sends the quantum signature to arbitration; And the receiver verifies the quantum signature under the constraint condition provided by arbitration. The protocol provided by the invention not only can ensure the security, but also has a better practical application value.