The acceptability of exhaust gas emission of acid regeneration line for cold-rolled process reaches the requirements of national new environment protection laws in Panzhihua Steel and Vanadium Company and Xichang Steel and Vanadium Company. By taking a series of measures, such as upgrading and revamping environment protection technology, iron oxide powder and hydrogen chloride concentrate in the exhaust gas of acid regeneration line of cold-rolled mill under Panzhihua Steel and Vanadium Company is much lower than the limit value of national emission standard, which is in the leading position in China. Xichang Steel and Vanadium Company keeps paying attention to the investment of environment protection during construction. Therefore, the exhaust gas emission concentration of acid regeneration line has been following the standards.