Aiming at achieving the technical aim of efficient high-quality finishing and flexible control over a complex surface, the invention discloses an automated magnetic field-aided finishing machining device and method. The device comprises an industrial robot, an industrial vibrating motor, a novel finishing machining device, a workpiece clamping device and a triaxial precision displacement worktable; the novel finishing machining device comprises a magnetic field generating device, a fixed plate, a connecting plate, guide screws and a connecting rod; the magnetic field generating device comprises linkages, guide rods, a magnet yoke, lead screws, handles, nuts, bolts, four magnetic poles and magnetic pole sleeves; by the industrial robot, multi-degree of freedom flexible regulation is realized, and automated finishing machining on workpieces different in surface profile can be completed; under the vibrating combined action of the industrial vibrating motor, finishing machining efficiencycan be increased; and feature surfaces of different workpieces can be regulated by angles of the magnetic poles of the novel finishing machining device. The device and method are capable of breaking through the limitation of finishing machining on the complex surface by the traditional method, and therefore, efficient high-quality flexible automated finishing machining is realized.