The deformation of laser bending is identified to be a result of the thermal strain and phase transformation strain through real-time measuring the dynamic micro-deformation of the specimen and microstructure analysis in the cross section of heated region center under the condition of laser-material non-melting interaction. Laser bending mechanism is described as Temperature Gradient Mechanism. When the temperature gradient is enough small, the thinner specimen produces the buckling due to lost steady state and the thicker specimen produces the upsetting due to compressed in the heated zone. Experimental results show that the deformation extent and direction of the specimen depend on the energy absorbed by the specimen, the composition peculiarity of the specimen and the specimen thickness, and give that influence factors vary with the laser bending deformation. The conclusion reveals the mechanism of laser bending and lays a foundation of research on the process of laser bending further.