The invention discloses an edema-proof foot support, which comprises a foot support tool and a knee pillow, wherein the foot support tool is used for supporting two feet of a patient; the knee pillow is used for supporting two knees of the patient; two arc-shaped grooves used for accommodating the two feet of the patient are formed in the upper side surface of the foot support tool in parallel and at intervals; and an adjustable belt used for fixing an ankle of the patient is arranged in each of the arc-shaped grooves. According to the edema-proof foot support, a timing edema-proof foot support is applied, so that legs and feet of the patient are supported; at the same time, demands of different body positions are met, limbs are placed in functional positions, and edema of lower limbs are relieved and controlled. A timer for reminding the patient to change the body position is arranged, so that the patient can turn over the body freely, the support is suitable for three body positions (a horizontal position, a left lateral position and a right lateral position), at the same time, materials are breathable, and the patient can use the support comfortably; wrapping cloth is detachable, so that cleaning and sterilizing are facilitated. In short, the edema-proof foot support is simple in structure, can be used and cleaned conveniently, and complicating diseases of pressure sores, venous thrombus and the like caused by lying in the bed for a long time can be prevented simultaneously.