The crystallization of Ti3Al amorphous alloy during tensile deformation was studied with molecular dynamics. The simulation results show that the crystallization of amorphous alloy is induced by the local plastic deformation. The microstructure evolution was analyzed in the tension process. It is found that the nucleation and growth are induced by the shear localization and the final crystal phase has fcc structure. It is also found that the crystallization process is accompanied by strengthening of the material. The nanocrystal grains embedded in the amorphous phase can enhance the rigidity of the sample.