In old age, body size, range of motion, flexibility, muscle strength and multiple sensory perception will basically change, and the physiological characteristics of the elderly will gradually degenerate or weaken with age. In addition, the elderly as a result of physical aging, bone support, muscle strength and physical toughness have decreased, and even cognitive decline. Therefore, it is one of the demands of the old users that the product design form should follow its physiological structure, that is, all kinds of design should be carried out in accordance with their physiological characteristics, and the relevant scale should be designed according to the size of the old people.