The invention relates to a method for precisely evaluating the sharpness of the pattern contour of printing gum. The method comprises the steps of (1) mixing the printing gum, and printing two groups of straight lines on a fabric, wherein each group consists of three same straight lines which are parallel to one another, one group consists of thin lines which are 10cm long and 100-400 microns thick, and the other group consists of thick lines which are 10cm long and 400-1,000 microns thick; (2) measuring the thicknesses of the lines on the fabric through an electronic microscope after the two groups of printed straight lines are dried, wherein the line thickness of a point is measured on each straight line at an interval of 1cm, and 30 points are measured on each group of straight lines; (3) calculating the line thicknesses and the non-uniformity so as to evaluate the sharpness of the pattern contour of the printing gum. According to the method for precisely evaluating the sharpness of the pattern contour of the printing gum, conventional visual measurement is changed into quantitative research; the method is simple and feasible; the fine pattern printing performance of the gum can be accurately reflected.