The invention provides a dedicated anti-scale agent for a sulfate section of a salt and sulfate co-production system. The dedicated anti-scale agent is prepared by mixing sucrose phosphate, sodium gluconate, a tartaric acid-malic acid-sodium hypophosphite telomer and purified water according to a certain proportion. Being added into a sulfate section mother liquid of the salt and sulfate co-production system, the anti-scale agent can effectively prevent Ca<2+> and Mg<2+> from generating non-soluble salt crystals, so as to avoid scaling, causing reduction of heat-transfer property and evaporation efficiency, of Ca<2+> and Mg<2+> in sulfate producing equipment, reduce cleaning frequency, remarkably prolong the operation cycle of the sulfate producing equipment, improve sulfate producing efficiency, and improve the quality level of a sulfate product. Moreover, the anti-scale agent can form a corrosion-resistant protecting film on the metal surface of the equipment, so as to reduce corrosion of the mother liquid to the sulfate producing equipment. Adoption in sulfate producing equipment in five salt and sulfate co-production enterprises in China shows that the effects of energy conservation, scaling prevention, stable yield and quality improvement are excellent.