Abstract: Nickel base superalloy is a kind of hard to machine metal material. It is difficult to guarantee the surface quality after using this material.The surface quality is an important content of micro machining, which has a great influence on the wear resistance, corrosion resistance and heat conduction performance of machined parts. In this paper, based on the analysis of cutting experiment results, micro cutting simulation is carried out to study the surface quality of nickel base superalloy during micro cutting. The results show that: During the micro cutting process, the grain of chip layer is broken and the chip accretion is formed on the front tool surface due to the high temperature softening. The chip accretion softens from the lower tool surface and remains on the machining surface to form a hard point burr. Because the size of the blunt radius of the cutting edge of the micro cutting tool can not be ignored, thus the plowing phenomenon occurs, that is, in the process of micro cutting, the grains in front of the blunt circle are squeezed by the cutting edge of the tool and pressed into the machining surface, forming a depression on the machining surface. The simulation results show that the formation of sawtooth chips is beneficial to reduce ploughing.