A scraping knife has been developed to better match modern silk threads with the warp and weft lines of silk cultural relics during the restoration of ancient silk paintings, in response to the different requirements for materials and mounting of ancient and modern times and various types of diseases. This knife is formed by a line or a surface with eight points as the scraping state, which can avoid the drawbacks of the commonly used tools for silk painting restoration, such as horseshoe knives and art knives, which have a small inclination angle force point and are difficult to control and can easily damage the painting core. Although this silk scraping knife has played a good role in restoring a Ming Dynasty silk painting, the scientific applications of Su Mounting technique as an intangible cultural heritage still needs to be continuously explored.