The infringement liability of the online live broadcast service platform mainly comes from the infringing interpretation of the works by the platform anchors in the performing arts activities. In practice，when the court determines the platform’s responsibility for the live broadcast of the host’s unauthorised songs，the court distinguishes between the platform’s service method and the host’s contracting method. Under the platform service mode，the platform，as a network service provider，has no direct control and decision power over the live broadcast behavior of the anchor，so the general duty of care should be applied. In the case of the anchor contract method，the online live broadcast platform and the anchor constitute a labor relationship，and they should bear legal responsibility for the infringement that occurs during the live broadcast of the network anchor. By analyzing the different legal relationships between the host and the platform，and distinguishing the different forms of tort liability that the platform should bear，it can better promote the healthy and orderly development of the Internet live broadcast platform.