A hair image display method comprises the steps of: selecting a hair area from a hair image; performing an edge detection on the hair area to calculate an edge image; performing representation processing on the edge image to calculate a representative value image; calculating direction differences between the edge image and the representative value image; and rendering the direction differences of respective pixels in color or grayscale to display a direction difference image, or rendering the correlation lengths of respective pixels in an edge direction image in color or grayscale to display a bundle width image, or determining the curvatures of the respective pixels in the edge direction image to form a curvature image. This makes it possible to display directions straying from a flow, bundles of hairs in the same flow, and the state of curls in hair styling clearly, and to facilitate evaluations of the hair styling.