The invention discloses an acousto-optical abnormal Bragg diffraction-based laser beam combination method, and belongs to the field of laser beam combination. The acousto-optical abnormal Bragg diffraction-based laser beam combination method comprises the steps of determining a wave combination intersection point with a target diffraction angle according to an acousto-optical Dixon equation diffraction curve corresponding to the wavelength of each incident light; acquiring frequencies of sound waves and incident angles of incident beams from the acousto-optical Dixon equation diffraction curveaccording to numbers of the incident light wavelengths, numbers of the incident beams, numbers of the incident beams with same wavelength and the beam combination intersection point with the target diffraction angle; loading the sound wave onto an acousto-optical crystal, wherein the incident beams irradiate the acousto-optical crystal at the incident angles; and generating abnormal Bragg diffraction between the incident beams and the source waves to form a combination beam with the target diffraction angle. The propagation direction of the combination beam can be accurately controlled by selecting the sound wave frequencies and adjusting the incident angles of the incident beams.