A sliding mode (SM) regulator was proposed for the turbo fan engine parameter limit protection. The feedback gains of the SM were designed using the regional pole placement method based on the mixed norm synthesis. The overall asymptotic stability of the SM regulator was established. The SM regulator was verified and compared in the simulation with different sliding switch gains

of which one of the gains was used as the standard coefficient for the following simulations. The regulating effects between SM regulator and linear regulator were compared and analyzed. The results preliminarily show that

the parameter limit regulator acts as a main control regulator during engine transient state process based on sliding mode control theory

overcoming the drawback of linear parameter limit regulator which nearly can not work during the same process; the designed regulator can conduct the parameter limit protection function in 7 seconds during the engine transient state.