In laser forming, except for the desirable bending deformation, the undesirable deformation is also produced. The undesirable deformation can be ignored in the conventional laser forming, however, for the high precision workpiece, these inaccuracies influence not only the assembly accuracy, but also the operational life. To reduce the undesirable deformation of the forming workpiece and seek for the optimal process technology, the temperature distribution of laser forming and restraining force variation of the surrounding cold material on the heated area are analyzed， the undesirable deformation mechanism is disclosed， and two new scanning strategies are proposed. The results show that the metal plates have the different undesirable deformation under the different scanning strategies. In real industrial applications, the different scanning strategies should be chosen according to the different forming requirements.