The invention belongs to the technical fields of non-ferrous metallurgy and chemical engineering and discloses a method for removing arsenic from an arsenic-containing copper sulfate solution by virtue of a wastewater arsenic settling residue. The method comprises the steps of mixing wastewater arsenic settling residue with wastewater arsenic settling residue, carrying out arsenic removal condition at controlled conditions, carrying out liquid-solid separation treatment, processing a filter-pressing residue, and the like. According to the method, the wastewater arsenic settling residue is utilized for replacing ferrous sulfate so as to remove arsenic in the arsenic-containing copper sulfate solution, the wastewater arsenic settling residue can be enriched, the arsenic content in the arsenic-containing copper sulfate can be reduced, the arsenic content in the arsenic residue after the enrichment reaches 18%-23%, and the residual iron content in the wastewater arsenic settling residue iseffectively utilized, so that the material cost is lowered, the total amount of hazardous waste is effectively reduced, and the arsenic removal cost of the wastewater arsenic settling residue is effectively saved.