In this paper, the acoustic emission response of single crystal γ-TiAl alloy during nano-cutting process is studied by molecular dynamics method. The mechanism of crack formation in the cutting process of single crystal γ-TiAl alloy is described at the atomic scale. It was found that periodic shear bands are formed in the shear zone with the continuous increase of cutting force at the beginning of cutting. At the same time, under the combined action of high pressure stress and elastic stress wave, the formation of the amorphous atomic band in the grain boundary blocks the continuous emission of the shear band, so that the stress in the main shear zone can not be released through the shear band in time,and result in local stress concentration, which leads to the initiation and propagation of cracks. By analyzing the acoustic emission signal collected, it was found that the compressive stress contributes to the decrease of acoustic emission power in cutting process. In the time domain, the acoustic emission response characteristics of lattice vibration, shear band and crack initiation and propagation in nano-cutting process are described by analyzing the microdefect evolution and AE power-frequency comparison. At the same time, the power and frequency characteristics of damage are obtained by clustering analysis.