The invention provides a triangular patient's face protecting film for a non-invasive ventilator and a designing method of the triangular patient's face protecting film. On the basis of the conventional square seepage absorbing film, two semi-elliptical eye socket outlines A, a
nose wing outline B and a
nose bridge outline C are respectively shorn off, and the triangular patient's face protecting film can be matched with the face of a patient. The triangular patient's face protecting film is characterized by consisting of a
forehead sticker (1), a
nose root sticker (2) and
cheek stickers (3). By using the triangular patient's face protecting film, the face of the patient can be prevented from being in direct contact with a
mask, and a phenomenon that the
skin of the patient is injured due to the fact that the
skin of the patient is irritated to be red, the patient perspires, and condensate water is not removed timely after the ventilator is humidified is avoided. The triangular patient's face protecting film has the advantages that the triangular patient's face protecting film cannot drop easily, the
sight of the patient is not blocked, and pressure on a compression face is low; the
sight of the patient is good; the patient cannot have pressing
sensation or feel uncomfortable; no matter whether the face of the patient is injured or not, the patient can use the triangular patient's face protecting film; and the triangular patient's face protecting film can well protect a
wound surface and prevent
pressure sores, and is clinically applied to a hospital of the applicant.