A main object of the present disclosure is to provide a method for producing a sulfide solid electrolyte material, the method that allows a concentration of lithium halide to increase and that allows drying at a low temperature. The present disclosure achieves the object by providing a method for producing a sulfide solid electrolyte material, the method comprising: a drying step of drying a precursor aqueous solution containing LiI, LiBr, and LiOH to remove water and obtain a precursor mixture; and an electrolyte synthesizing step including a sulfidization treatment to sulfurize the LiOH in the precursor mixture and obtain LiHS, a de-sulfide-hydrogenating treatment to desorb a hydrogen sulfide from the LiHS and obtain Li2S, and a synthesizing treatment to make the Li2S to react with an auxiliary material; wherein a molar ratio of the LiOH with respect to the LiI and the LiBr, LiOH/(LiI+LiBr), in the precursor aqueous solution is 3 or more and less than 6.