Method for debugging light beam directivity of zoom beam expander

The invention provides a method for debugging the light beam directivity of a zoom beam expander. The method comprises the steps that collimation adjustment is conducted on a zoom beam expander on an adjusting frame, wherein the zoom beam expander comprises a first lens, a second lens, a third lens and a fourth lens which are arranged in the transmission direction of incident light; a light spot analyzer is arranged in the light path transmission direction of the zoom beam expander, and an initial value of a light spot energy center coordinate value displayed in the light spot analyzer is recorded as a first coordinate value; the magnification of the zoom beam expander is changed to obtain a second coordinate value of the light spot energy center; and the distance value between the first coordinate value and the second coordinate value is a deviation value, when the distance value is out of a preset range of the deviation value, the position of the fourth lens is continuously adjusted through the adjusting fr