Abstract: The fluorescent penetrant inspecting contrastive experimentation is performed on titanium alloy fatigue crack samples of different surface states as treated by the blowing sand, burnish, chemical etching, vacuum heat treatment, shot peening and so on. And the defect areas are inspected by scanning electron microscope,then the result is finally got. The results indicate that the cracks will be easily jammed by blowing sand and especially shot peening resulting in defects undetected. The defects will not obviously be jammed by burnish and vacuum heat treatment. Moreover defects will be exposed richly and shall be easy for the inspection after chemical etching treatment.