A new structural method of laser additive manufacturing (LAM) with four-wavelength laser, multi-tube dusting, and quasi-six-degree-of-freedom numerical control motion is proposed. The overall system architecture is analyzed in terms of linear space and Lie subgroup function. A linear and spatial mathematical model for this system is established. The components of Nd-Fe-B rare earth permanent magnets are sprayed quantitatively by using the multi-dusting mechanism. In addition, by the control of the powers and angles of four laser beams, the selective and directional laser irradiation is conducted, and the LAM of heterogeneous permanent magnetic parts is realized with forming accuracy of 20 μm, minimum width of less than 80 μm, and magnetic energy product of 474 kJ·m 3.