A calculation method for viewing-angle compensation of a display device, a viewing-angle compensation structure, and a display device is disclosed. The method includes: measuring tristimulus values for red, green, and blue displayed in grayscale of a display device in a viewing angle and a luminance gamma curve; calculating a central viewing angle, a first viewing angle, and a second viewing angle of an observation viewing angle of the display device, to obtain a viewing angle range of the observation viewing angle; obtaining a display look-up table (LUT) by using an angle of the viewing angle and the luminance gamma curve and according to a viewing angle algorithm; then obtaining a viewing-angle compensation value by using the central viewing angle and the viewing angle range and according to the display LUT; and eventually adjusting the corresponding tristimulus values in the display device according to the viewing-angle compensation value.