Deform3D numerical simulation software was used to simulate the dynamic deformation, internal stress, microstructure damage, dynamic strain and plastic deformation differences of the hotrolled specimens in the high temperature compression tests using a thermal simulation testing machine (Gleeble 3500). The results showed that the surface area of the sample first decreased and then increased in the process of compression. The surface area was the minimum at about 5 s, and the decrease percentage was 4.1%. Then it increased sharply after 8.4 s with the increase percentage of 14.4%. In the whole compression stage, the maximum stress on both ends of the specimen was about 70 MPa. The value of destructive damage (Damage) was 0.22, the strain was 1.43, and the maximum deformation rate of the top region was 1.19 mm/s. In the process of air cooling and quenching, the temperatures in the corner region of top and bottom boundary surface decreased fastest. The change trend of hightemperature region was transformed from rectangle to rounded rectangle, and then to ellipse.