The invention provides a method for preparing vanadyl sulfate through solid phase roasting.The method includes the following steps that vanadium pentoxide, sulfuric acid with the concentration larger than or equal to 98wt% and a reducing agent are mixed to be uniform and then placed in a closed container; the closed container is placed into a heating furnace to be subjected to temperature raising and roasting and a reduction reaction; after the reduction reaction is completed, reactant in the closed container is dissolved in water with the temperature being 70-100 DEG C, stirring and filtering are conducted, and a vanadyl sulfate solution is obtained; seed crystals are added to the vanadyl sulfate solution, then cooling crystallization is conducted, and vanadyl sulfate crystals are obtained.By means of the method, the defect that jelly or a substance similar to jelly is generated easily in the process of preparing the vanadyl sulfate from a dilute sulphuric acid solution is overcome, the prepared vanadyl sulfate crystals have large crystalline grains, equipment is simple, the reaction condition is mild, operation is easy and convenient to conduct, the cost is low, and large-scale production is achieved easily.