A periodic pulsating incoming flow was used to simulate the flow field at the outlet of a rotating detonation combustor. The effect mechanism of the amplitude and frequency of the incoming pulsation on the unsteady internal flow characteristics of the GE-E3 high pressure turbine stage was studied. Results indicated that the increase of the pulsation amplitude of the inflow could enhance the unsteadiness of the internal flow field and amplify the difference of the parameters in the internal flow field in time and space. With the increase of the pulsation frequency

the pulsation amplitude of the internal flow field gradually weakened

and the distribution of the time averaged loading of the blade was inclined to be consistent. Under the condition that the incoming pulsation frequency was 5 244 Hz

when the pulsation coefficient increased to 04

the turbine efficiency was reduced by 1399%; under the condition that the incoming pulsation coefficient was 03

when the pulsation frequency increased to 10 488 Hz

the turbine efficiency was reduced by 1557%. Increased pulsation amplitude and frequency could enhance the endwall secondary flow and cascade flow separation

make the inlet attack angle of blades deviate from the design state

and reduce the turbine working efficiency.