Method for deeply removing arsenic from arsenic gypsum

The invention relates to high-added-value comprehensive utilization of arsenic gypsum, relates to a method for efficiently removing arsenic from the arsenic gypsum, and particularly relates to a method for deeply removing arsenic impurities in the arsenic gypsum and preparing high-quality high-added-value gypsum at the same time. According to the method, firstly, part of arsenic impurities in the arsenic gypsum are removed through acid leaching pretreatment, then, the arsenic impurities in gypsum inclusion and crystal lattices are fully released through the dissolution process of gypsum phase regulation and control, and meanwhile, the existence form of arsenic in a solution is regulated and controlled to prevent the arsenic from entering the gypsum crystal lattices again in the recrystallization process; and a crystal form regulating agent is added to regulate the morphology and granularity of a recrystallized product so as to weaken the adsorption of arsenic on the surface of a gypsum product, finally, effic