Abstract: A turbocharger turbine was proposed based on the concept of elastically restrained guide vane.Firstly,the unsteady characteristics of elastically constrained guide vane turbine and the influence of pulse amplitude and frequency on its performance were studied based on fluid structure coupling (FIS) method.And then,comparing with the traditional variable nozzle turbine (VNT),the new VNT was investigated to analyze the reason of its performance change.The comparison results show that,the smaller the pulse amplitude and the lower the frequency,the flow rate of the new VNT is higher,the output power increase rate is higher,and the efficiency decrease rate is lower.Based on the inlet flow angle and the stator outlet pressure loss distribution,the influence of pulse amplitude and frequency on elastically constrained guide vane turbine performance can be concluded.