The invention relates to a zinc hydroxylfluoride hyperbranched composite nanostructure and a synthesis method thereof, which belong to the technical field of group-IIB hydroxylfluoride nanomaterials.The hyperbranched composite structure zinc hydroxylfluoride nanocrystal is composed of a large quantity of nano-lines which are radially scattered from the same node to all the directions of a three-dimensional space, and has the characteristics of bulkiness, multiple voids, large surface area and the like. The synthesis method comprises the following steps: firstly, CTAB (cetyl trimethyl ammoniumbromide) is diluted with deionized water, then added with zinc acetate dihydrate and HMT (hexamethylenetetramine), stirred and then added with sodium fluoride; secondly, hydrothermal reaction is carried out in a reaction kettle; finally, deionized water is used for washing, and after drying, a white powdery sample is obtained. The invention synthesizes the zinc hydroxylfluoride hyperbranched composite nanostructure for the first time, the surfaces of the nano-lines are even and smooth, and the morphology is uniform; the synthesis method is simple, pH value does not need to be regulated, the repeatability is good, the cost is low, the yield and purity of product are high, and a better morphological condition is provided for the further synthesis of ZnO.