A method for forming patterns on face membrane by air-drawing force when vacuum. A foamed polyurethane (PU) is injected on the surface of substratum cloth to form a face membrane. The face membrane is heated at a preset temperature by a preheating box to be continuously maintained in a softened condition before it is not thoroughly hardened. An airproof release film is attached on one side of the substratum cloth opposite to the face membrane. A roller having functions of vacuum and cooling has its superficial patterns being pressed and printed on the heated face membrane by the air-drawing force when vacuum.