Abstract: A method for circularly purifying metallurgical arsenic-containing acidic waste liquid and recovering sulfur, including the following steps: (1) adding a calcium-free arsenic removal agent into the metallurgical arsenic-containing acidic waste liquid for stirring reaction, and filtering the reaction mixture to obtain arsenic-containing slag and a purified liquid; (2) adding calcium hydroxide into the purified liquid for secondary stirring reaction, and performing sedimentation and separation on the mixture to obtain a supernatant and a subjacent concentrated slurry; and refluxing the supernatant to a pretreatment workshop; (3) introducing the subjacent concentrated slurry into the metallurgical arsenic-containing acidic waste liquid, performing stirring reaction, and filtering the reaction mixture to obtain a liquid phase and a slag phase; and (4) washing the slag phase with water to obtain a gypsum product; refluxing the washing liquid to the pretreatment workshop; and taking the liquid phase as a raw materi