The invention provides a gamma-
cyclodextrin crystal form A and a preparation method thereof, an X-
ray powder diffraction pattern of the gamma-
cyclodextrin crystal form A has characteristic peaks when a 2 theta value is 9.15 + / -0.2 degrees, 12.04 + / -0.2 degrees and 16.35 + / -0.2 degrees, and the preparation method comprises the following steps: adding a certain amount of gamma-
cyclodextrin into a certain amount of water, stirring, and carrying out
ultrasonic dispersion to obtain a gamma-cyclodextrin
crystal form A; the preparation method comprises the following steps: covering a
bottle with a cover, heating in a biochemical
incubator, dissolving, filtering a dissolved clear solution into a nuclear
magnetic tube, adding a certain amount of hydroxypropyl
methyl cellulose, vacuumizing, introducing
nitrogen, fastening a rubber plug, heating in the biochemical
incubator, setting heating and cooling procedures of the biochemical
incubator, crystallizing, separating out white cluster-shaped solids at the bottom of the
bottle, and
drying, thereby obtaining the white cluster-shaped
solid. And separating out a
solid to obtain the gamma-cyclodextrin crystal form A. The crystal form A is low in energy, more stable, higher in stacking density and convenient to
package, transport and store.