In order to understand the turbofan engine performance change after swallowing water，the test of one turbofan engine performance change after swallowing water was designed and carried out on the conventional testing facility. When the engine was at idling，throttling，max speed，and afterburning，the mass of swallowing water was 2%

3.5% and 5% of the inlet air mass flow. The test results showed that: at the idling，the lowering degree of the inner and outer culvert outlet temperature of the fan did not change with the change of the mass of water swallowing，after swallowing water the engine thrust decreased about 20% at most；at the afterburning，the decreasing degree of the outer culvert outlet temperature of the fan grew with the increase of the mass of water swallowing

after water was swallowed

due to the low-pressure speed increase，engine thrust increased about 15% at most. No stalling

surge and flameout of the combustion chamber of the engine were caused during the swallowing process. Engine performance did not deteriorate after water was swallowed.