The invention discloses a cutting edge contact distinguishing method for flat-end end mill strip maximization machining, and belongs to the technical field of milling machining. A cutter contact interface analytic model is established by aiming at the flat-end end mill strip maximization machining, one of the following two conditions needs to be met to judge whether one point on a cutting edge is in contact with a workpiece or not on the basis of the established cutter contact interface analytic model: a radial position angle corresponding to the point is positioned within a radial position angle range corresponding to an intersection circular arc curve, and the point is positioned below the circular arc curve; and the radial position angle corresponding to the point is positioned in the radial position angle range corresponding to an intersection elliptic arc curve, and the point is positioned below the elliptic arc curve. By use of the method, through a mathematical analysis method, whether a cutting edge point is in contact with the workpiece or not is judged, the method has the characteristics of being high in efficiency and accuracy, in addition, the method can be expanded to the multi-axis numerical control machining of a general hook face on the basis of a differential discrete thought, and the method has a wide application prospect in the field of the cutting dynamics of the flat-end end mill.