Abstract:The excellent mechanical properties of nickel base single crystal superalloy are mainly due to its ordered L12 structure γ? (Ni3Al). In order to study the effect of laser shock γ?, the molecular dynamics model of single crystal Ni3Al was constructed by molecular dynamics method, and the microstructure evolution behaviors of [100], [110] and [111] were analyzed. The results show that the plastic deformation mechanism of [100] crystal shock is the transformation from FCC phase to BCC phase, and the content of BCC phase increases with the increase of shock pressure; The plastic deformation mechanism of [110] and [111] crystal direction shock is dislocation slip, and the [110] crystal direction slip system is mainly (1)[011] and (11)[01], The [111] crystal slip system is mainly (1)[10] and (11)[101],the dislocations produced are mainly 1/6<112>(Shockley). However, with the increase of impact pressure, the plastic deformation mechanism is the transformation from FCC phase to BCC phase, and disordered structure is produced at the same time.