Bending 3D free form metal plates is a common process used in many heavy industries such as shipbuilding. The traditional method is the so-called line heating method, which is not only labor intensive but also inefficient and error-prone. This paper presents a new incremental bending method based on minimum energy principle and model-less control method. First, the sheet metal is discretized into a number of strips connected through virtual springs. Next, by applying minimum energy principle, the punching and supporting points are calculated for each strip. Then, the bended shape of the strip is computed based on the beam bending theory. This process is continued until the final shape is reached. To compensate the bending error, the computer vision based model-less control is applied. The computer vision detects the bending error based on which additional bending steps are calculated. The new method is tested in a custom build incremental bending machine. Different metal plates are formed. For a metal plate of 1000 × 800 × 5mm, the average bending error is less than 3mm. In comparison to the existing methods, the new method has a number of advantages, including simple, fast and highly energy efficient.