In shipbuilding industry, it has been generally accepted that as long as thin steel plates are used, the ship deck will be deformed, and this deformation will not be completely eliminated. However, after discovering the root cause of the deformation, we found one of the most economical and management-effective Terac thermal leveling methods. In the past, due to the lack of knowledge of thermal flattening of thin plates or control means of heating process, the thermal deformation of stiffeners on thin plates will be more serious in some cases. However, the application evaluation of Terac induction heating system shows that this method greatly reduces the leveling time. In addition, the influence of induction thermal flattening on the properties and microstructure of thin plate materials is also evaluated. In each evaluation, there were no adverse effects.