The invention discloses a technical scheme. In the technical scheme, positioning mark points and positioning mark lines in medical robot navigation positioning images collected from a C-shaped arm X-ray machine are picked automatically, accurately and efficiently by using multiple image processing technologies comprehensively. The processing processes comprise the following steps of: inhibiting noise by using an image enhancement method first within the actual imaging range in the images, highlighting targets and enhancing contrast of foregrounds to backgrounds; segmenting the foregrounds andthe backgrounds by using the image segmentation technology, and using the contents of the all foregrounds as an alternative area; performing number marking of a communication area on the alternative area; acquiring candidate mark points through template matching, and detecting the mark lines on the peripheries of all the candidate mark points; and finally determining the accurate mark points by using shape discrimination, and determining the grouping and number of the mark points by utilizing the mark lines.