The invention provides a method for selecting and identifying a target fringe in an interference fringe method, comprising the following steps: acquiring a background image before voltage applying in a uniform electric field, and extracting the skeleton line of bright fringes in the background image; selecting one bright fringe from the background image as a target fringe; setting a pixel interval according to the target fringe, and acquiring the reference row coordinate of the midpoint of the pixel interval; acquiring a compression image after voltage applying in a uniform electric field, and extracting the skeleton line of bright fringes in the compression image; setting a reference line vertically passing through the midpoint of the pixel interval in the compression image, and acquiring the moving row coordinate of the intersection of the reference line and each fringe; and working out the difference between each moving row coordinate and the reference row coordinate, wherein the fringe of which the difference is smaller than a preset range is the target fringe after moving. The invention further provides a system for selecting and identifying a target fringe in an interference fringe method. The displacement of a target fringe can be acquired accurately.