Secondary bending forming method of T-section profile and bending die

The invention provides a secondary bending forming method of a T-section profile. The method is characterized in that a bending die and a snake-shaped filling body are arranged on the basis of a profile bending device; the section of the filling body is matched with a V-shaped cavity in the upper end of the Y-section profile; the Y-section profile which is bent and deformed for the first time is discharged from the bending device and then thermally processed until reaching a new quenching state, and the Y-section profile in the new quenching state is bent for the second time; the total time from the first bending, discharging, thermal processing to the second bending is not greater than 150min.