Abstract: Aiming at the cracks in the vibration fatigue test of the integral ring blade after the forging heat treatment and hot isostatic pressing process, this paper uses macro inspection, fracture macro and micro analysis, material analysis, mechanical performance test and finite element stress simulation to analyze and study the crack properties and initiation causes of the blade, and put forward suggestions for improvement. The results show that the crack property of the integral ring blade is high cycle fatigue fracture. The fatigue crack originated from the maximum stress area on the back surface of the blade. Furthermore, there was a continuous α film with straight grain boundaries, and the fatigue resistance was significantly reduced, resulting in the premature initiation of fatigue crack.