This paper researched the behavior of CRP1000 nuclear power plant steam generator tube rupture(SGTR) accident with full scope simulator(FSS).Two different conditions of SGTR,without intervention in 1.5 hours after SGTR and with operator intervention according to operation specification are calculated.Results have been compared with the reference accident analysis report to verify this simulator.Tendency and reasons for the change of important parameters have been studied and analyzed,and the entire incident sequence and operation intervention are given.