Abstract: During the test run of an engine turbine blade, some falling blocks and cracks appeared at the edge plate. Macro analysis, macrocorrosion and fracture analysis were used to analyze the causes for the falling block at the turbine blade edge plate. The results show that the quality of turbine blade edge plate falling block and crack was permanent fracture failure, and the cause of turbine blade edge plate crack was related to the angle of low-angle grain boundary at edge plate was too large. It is suggested that the technical requirements for low-angle grain boundary of this turbine blade should be raised from no more than 8° to no more than 6°.