3D laser cutting has been widely used in automobile and aerospace industry. In 3D laser cutting it is inevitable for laser head to move up and down, keeping the laser head vertical to the surface of workpiece. The orientation of laser head influences cutting result. In order to quantitatively analyse the relationship between cutting result and cutting parameters, the 10 marks quality-evaluation system of cutting result and ANN(artificial neural network) have been setup. The new knowledge can be introduced by ANN. These new knowledges have been used to guide actual cutting to realize intelligent laser processing.