The invention discloses a recycling method of arsenic-containing gypsum slag. The arsenic-containing gypsum slag is arsenic-containing gypsum slag produced in a waste acid neutralization process. Therecycling method comprises the following steps: (1) carrying out reduction roasting on the arsenic-containing gypsum slag by adopting a carbon reduction agent, so as to obtain arsenic-containing fluegas and roasting slag; (2) carrying out flotation separation on the roasting slag obtained in step (1), so as to obtain calcium sulfide concentrate and calcium fluoride slag. According to the recycling method disclosed by the invention, path opening of arsenic and fluorine in the gypsum slag and recycling of valuable metal are realized; influences caused by the fact that a lot of the arsenic-containing gypsum slag dangerous wastes are stacked and stored on the environment are solved, and the recycling method also has good economic and environmental benefits.