With rapid prototyping the rapid development of the industry, reverse engineering, rapid prototyping in the field has become increasingly important role. It as a new product design ideas and methods widely used in the field of rapid prototyping, and achieved many results. This paper presents a profile of reverse engineering and key technologies, and human model and ear plugs reverse design, It includes the basic model of the human ear plugs and surface model data measurement, data post-processing, Reconstruction of the surface model and structure design. Focus on the laser-based measurement technologies, and data measurement methods, Definitive CAD software platform for the various dimensions method, which was the best plan.