In order to study the processing adaptability and influencing factors of discharge induced combustion with function electrode for difficult to machine materials，contrast experiments between conventional electric dischar ge machining (EDM) with cylindrical electrode and combustion machining with func tion electrode are carried out. Four typical di f ficult to machine materials， i.e. nickel base superalloy GH4169， die steel Cr 1 2， titanium alloy TC4 and titanium aluminum alloy TAC 2 are selected in the co ntrast experiments. The results show that the efficiencies of combustion machining for GH 4169 is 112 mm3/min， for Cr12 is 92.28 mm3/min， for TC4 is 347.7 mm3/min an d for TAC 2 is 152.5 mm3/min， which are 37.3， 13.5， 58.7， 13.7 times than tho se of conventional EDM respectively under the same conditions. With the augmenta tion of metal activity， the burning intensity and combustion hot melting increas e and the combustion effect also becomes more apparent. The characteristics of oxidation l ayer covering on machining surface plays a significant role in improving alloy m aterial processing efficiency.Some factors determine the relative wear of the el ectrode，which include the weakened phenomenon on anti plating of inner ejection liquid，the improvement of ablation processing efficiency，the characteristic of the oxide layer，etc.