Abstract: Abnormal phenomena of detonation and fuel-rich were observed when the anti-surging regulator was employed to reduce the fuel during the grand test of an aero-engine.In order to solve this problem,a dynamic simulation of the anti-surging process was conducted using the AMESim software.The simulation has showed that the AMESim software can deal with such hydro-mechanic dynamic process.The dramatic change of the fuel pressure,which results in unstable burning,causes these abnormals,but tyey can be alleviated if the diameters of the main throttle and the auxiliary throttle are properly changed.