The existing medical device products are generally determined by setting the size of the model, so the products may not fit with the body parts of the patient, resulting in unconspicuous protection and rehabilitation effect. By using reverse engineering technology, the personalized medical device design method based on Geomagic Deign X was proposed. Taking the design of foot brace as an example, by scanning the human foot with a body scanner, the point cloud data were processed，the surface model of the foot was generated via mesh fit. On this basis, the needed surfaces were cut out to get the basic model of the device, then the subsequent design was completed according to the requirements of patients and doctors. The combination of reverse modeling and forward design is realized. It provides a convenient and efficient method for the design of personalized medical device products.