Abstract: In order to solve the problems of functional modeling, structural expression and design reasoning of workpiece location in conceptual design, based on six point location principle, combined with cybernetics, the location model of workpiece is established, and the location of workpiece is divided into barycenter position location, surface set orientation location, and workpiece shape location, the concepts of constraint degree, location degree and dislocation degree are put forward, the function model, control model and design process model of six point location principle are established and analyzed, five principles of location design are summarized, the design method using virtual rigid body as intermediary is proposed, the six point location principle is extended to support the location of non-rigid workpiece, location system evolution that driven by dislocation degree are used for guiding location oriented structural design. Finally, the feasibility of the method is proved through the example of electric eggbeater design.