In order to study the dynamic characteristics of turbine flowmeter under pulsating flow, the pulsating flow field in turbine flowmeter is simulated by FLUENT software. In the study, the instantaneous output flow of turbine flowmeter under different pulsation amplitude and frequency is obtained，and the average value, pulsation amplitude and initial phase of the output flow under different conditions are obtained by sine function fitting. Then the amplitude-frequency characteristics and phase-frequency characteristics of turbine flowmeter are analyzed. The amplitude-frequency characteristics decrease linearly with the pulsation frequency, while the phase-frequency characteristics increase with frequency and then tend to be stable.