The human body in bed to maintain the normal physiological convexity of the cervical spine, in line with the physiological requirements of the cervical spine; so that the muscles of the neck, intervertebral discs, ligaments, etc. are in a natural relaxed state of rest. The pillow is too high or too low is not suitable. Generally speaking, the height and softness of the pillow and each person’s fat and thin, the width of the shoulder, the length of the neck, in order to be comfortable, and there is no certain uniform standard. The length of the single pillow should be more than their own shoulder width of 15 cm is appropriate. For people who are used to lying on their backs, the height of their pillow should be compressed and their fist high equal to appropriate; and people who are used to sleeping on their sides, the height of their pillow should be compressed and the height of their side of the shoulder width is the same as appropriate.