The acidic wastewater discharged from the nonferrous industry contains multiple metals with extremely complex components. Due to the low solubility product of metal sulfides, traditional sulfidation methods are prone to supersaturation, leading to coprecipitation. The efficient separation and resource utilization of multiple metals have always been an internationally recognized challenge. In response to these challenges, the research team has pioneered a novel idea for the cascaded separation and recovery of multiple metals through gas-liquid sulfidation. Studies focused on sulfide separation, particularly copper-zinc and copper-arsenic, were conducted. Our team established the relationship between hydrogen sulfide-enhanced mass transfer and sulfur concentration control, elucidated the characteristics of the gas-liquid-solid three-phase interface, revealed the sulfurization reaction mechanism,achieving efficient separation and recovery of metal sulfides. Compared to the current sodium sulfide method, the developed jet gas-liquid mixer and cascaded sulfidation reactor exhibited a tenfold increase in reaction rate. Direct separation of multiple components in acidic waste solutions has been realized, achieving a separation rate of 99% for challenging elements such as copper-arsenic and copper-zinc. The new technology and equipment have been implemented in over 20 national industrial applications. Internationally, this approach stands as a pioneer in achieving clean recovery of smelting acid and substantial reduction of hazardous waste.