Abstract: The gas turbine blades of aero-turboshaft engine need to withstand severe loads during operation, and its working reliability directly affects flight safety. Aiming at the fracture fault of the gas turbine blade of turboshaft engine, the fault causing components are determined through failure analysis of the fault components, engine parameter interpretation, retesting of test data and comparative testing of the entire engine in series. Combined with the combustion chamber performance simulation calculation results and the combustion chamber component performance test results, the fault failure mode is further confirmed. The main reason is the oversize of the swirl groove on the outer wall of the flame barrel, which results in the uneven temperature field at the outlet of the combustion chamber. The radial temperature distribution coefficient RTDF causes the high-temperature zone to shift towards the high stress zone of the gas turbine blades, which leads the blades deviation from design stste and early failure. The measures such as 100% reinspection of the swirl groove size and increasing the temperature limit at the outlet of the gas turbine have effectively reduced the manufacturing dispersion of the engine and improved the working reliability of the hot end components of an engine.