High cycle fatigue crack is found in compressor drums labyrinth seal tip during gas turbine performance test.The root cause is identified as wake flow excitation through modal and engine dynamic test.Then the structure is modified aiming to change the loading and resonance frequency of the seal.The effectiveness of the modification is testified that the resonance level decreased with additional weight.Different from engine test,oil impingement dynamic spin rig with slow ramp rate and precise speed control is proposed to investigate the effectiveness of viscoelastic material(VEM)damping,which is adhered to the inner ring of the drum,aiming to absorb the energy of excitation.The result shows that structure modification and VEM damping could both reduce the resonance level while the later method maintains the structure with less weight penalty.