Disclosed is a method and chip for vertically filtering an image, including: caching and reading image data; calling a filter to vertically filter the image data to obtain first filtered data; updating the image data according to the first filtered data, and judging whether a to-be-read row is the last row of the image data; if not, updating the to-be-read row to the next row of the to-be-read row, and returning to execute the step of caching the image data; and if so, determining the vertically filtered image data. In the present application, point-by-point feedback is changed to row-by-row feedback according to an algorithm principle of a digital recursive filter and the characteristics of an image chip.