The textile industry's wet processing division requires a significant amount of water and energy. Furthermore, the textile sector produces a substantial amount of wastewater. Consumer awareness, environmental rules and regulations, scarcity of water, and high energy costs have compelled textile producers to cut their water and energy consumption. Altering chemical finishing processes from traditional water-assisted systems to foam-assisted systems is another option to reduce water and energy usage in the textile industry. As one of the major components of supercritical CO2 dyeing apparatus, the separator performs the role of separating CO2 and dyes, influencing CO2 reutilization and subsequent dyeing production.The review cotains comparing between traditional and supercritical dyeing, advantage of supercritical dyeing and dyeing process and foam dying technology, principl and application.