The digital image correlation (DIC) technology has been used to track promptly the strain distribution and local strain evolution under different strain rates in this paper, and the propagation behavior of strain distribution and its strain rate sensitivity have been investigated. And the electron backscatter diffraction (EBSD) has been selected to analyze the microstructure evolution, the distribution of stress induced α" martensite transformation (SIMT) and martensite twinning after deformation. Besides, the scanning electron microscope (SEM) has been adopted to observe the fracture morphology of the material. The following conclusions can be drawn: (1) The strain distribution evolved from an approximate uniform distribution to a non-uniform distribution, then showing a phenomenon of strain concentration, and ultimately occurring fracture in the strain concentration area, and the significanted necking phenomenon has been displayed at the low strain rates. (2) A clear double yield phenomenon has been exhibited in the stress-strain curves with producing higher strain hardening rates at the low strain rates, it means that the materials show a negative strain rate sensitivity effect. (3) The content of α" martensite increased significantly, the grain size refined obviously, and the average values of KAM (Kernel average misorientation) and GNDs (Geometrically necessary dislocations) increased dramatically with the strain rate decreasing, it indicates that the SIMT increase can contribute to the accumulation of dislocation density in the deformed sample and be more conducive to the coupling effect of multiple plastic deformation mechanisms. (4) The fracture morphology mainly occur tensile fracture by the aggregation of ductile dimples and voids. The stress on the dimples rapidly develops from unidirectional tension to triaxial tension resulting in sufficient growth of the dimples during the deformation process. Therefore, the ductile fracture characteristics dominated in the low strain rates deformation with promoting the occurrence of this phenomenon.