The invention discloses a punching roller wheel mechanism of an automatic shaping mechanism, which comprises an upper rotary shaft and a lower rotary shaft located at the lower part of the upper rotary shaft; a left roller wheel and a right roller wheel are fixedly sleeved on the upper rotary shaft, and a lower roller wheel is fixedly connected to the lower rotary shaft; the upper rotary shaft and the lower rotary shaft are driven to rotate through an upper motor and a lower motor; pillar faces of the left roller wheel and the right roller wheel of the punching roller wheel mechanism are equipped with rolling structures, and each rolling structure comprises multiple pressing blocks with different shapes; the pressing blocks comprise strip pressing blocks, polygonal pressing blocks and circular pressing blocks; multiple pressing blocks of the same roller wheel are located on the same circumference. Through punching multiple grooves with different shapes on the surface of a section bar by means of multiple pressing blocks, multiple bulges with different shapes can be formed on the section bar; for the buckling forces and the directions generated by the bulges with different shapes are different, a waterproof strip or a damping strip can be more effectively buckled on a framework coating edge, thus the waterproof strip or the damping is not easy to fall down.