The invention provides an image sensor surface scratch detection method which comprises the following steps: (1) setting a scratch judgment area, and defining the number of pixels in the area as N andthe pixel value of a scratch part as a fixed value P; (2) setting a global storage area for recording the pixel value condition of the scratch judgment area; (3) collecting a plurality of images, reading the pixel value of the scratch judgment area, judging whether the pixel is a scratch position or not according to the pixel value, and recording a result in a global storage area; and (4) obtaining the scratch proportion of the surface of the sensor by dividing the number of pixels of the scratch part by the number of pixels of the whole scratch judgment area, and watching the scratch position of the sensor through the record of the scratch part in the global storage area after a plurality of images are displayed and acquired by using a bmp map. By means of the method, targeted suggestions can be provided for judging whether related components of the image sensor need to be replaced or not, the use cost of a user is effectively reduced, and product use reliability is improved.