In order to comprehensively evaluate the material removal rate, surface quality and electrode loss in the process of short arc machining nickel base superalloy, the orthogonal test of the adjustable process parameters of peak current, pulse width, duty cycle and voltage is carried out on the new type Numerical Control (NC) short arc milling machine. Experimental data were analyzed by using grey theory. The complex multi process target was transformed into a single evaluation index, i.e. grey relational grade. The test process could be greatly simplified by the method, and finally the optimal combination of process parameters was gotten. The experimental results show that the combination of parameters can improve the machining efficiency and reduce the electrode loss under the premise of ensuring the surface quality.