1. A virtual glasses try-on method, comprising the steps of: defining a first feature point of one lens of a pair of lenses of at least one glasses model, and a second feature point at a center of a frame of the glasses model, and obtaining a third feature point at an intersection of vertical vectors of the first feature point and the second feature point; capturing a user's image, and detecting a face image from the user's image; searching two eye images in the face image; binarizing the eye image to form a binarized picture, and dividing the binarized picture into an eye area and a non-eye area; defining an utmost right end and an utmost left end of the eye area as a first extreme value and a second extreme value respectively, and finding a center point between the first extreme value and the second extreme value; obtaining an intersection of vertical vectors of the first extreme value and the center point to find an example point; and performing an affine transformation of the first feature point, the second feature point and the third feature point of the at least one glasses model respectively corresponding to the first extreme value, the center point and the example point and superimpose the at least one glasses model onto the face image to form a try-on image.