Abstract: The present disclosure provides a successive gas path fault diagnosis method with high precision for gas turbine engines and falls within the technical field of fault diagnosis for gas turbine engines, including the following steps: establishing an engine nonlinear component-level model; capturing dynamic effects of an engine transient maneuver; outputting an estimated value of an engine observation parameter by the engine nonlinear component-level model; acquiring a measurement of the engine observation parameter through sensors; and iteratively updating a degradation factor through a solver. The present disclosure captures the dynamic effects of the transient maneuver at consecutive moments through time-series gas path measurement parameters, thereby realizing successive and high-precision diagnosis for health conditions of the gas turbine engines. This technology can provide a new successive and high-precision diagnosis method for the gas turbine engines under steady-state and transient conditions.