The invention discloses a method and a system for throwing simulation in breakage of high-energy pipelines for nuclear power plants. The system comprises an annular pipe network, an anti-throwing limiting part and a pressurizing device. The annular pipe network is provided with a nick for guiding pipeline breakage; the anti-throwing limiting part is arranged close to the nick and used for limiting throwing of a pipeline break end; the pressurizing device is connected with the annular pipe network through a pressure supply pipeline to provide a pressure for a medium in the annular pipe network. Compared with the prior art, the method and the system for throwing simulation in breakage of the high-energy pipelines for the nuclear power plants have advantages of accuracy in reflection of throwing load attenuation and changes at break ends of the high-energy pipelines.