Abstract: The crack of a fan stator blade of aero-engine was analyzed. The crack mode and cause were identified by visual inspection, fracture analysis, surface microscopic inspection, section metallographic examination, material analysis, chemical composition analysis and vibration stress distribution calculation of the corner of exhaust side of edge plate. Results indicate that the crack of fan stator blade edge plate was high-cycle fatigue crack. The welding heat-affected region of casing and edge plate entered into the stress concentration region of the corner of exhaust side of edge plate, which was a critical factor leading to the earlier fatigue cracking. The vibration loading accelerated the fatigue crack. Finally, the improvement proposal was put forward that the distance between the corner of exhaust side and welding should be increased.