Abstract: When astronauts move in manned spacecraft,they need to remove CO₂produced by crew's respiration and metabolism in time with the help of environmental control and life support equipment.The selection of CO₂removal equipment depends on mission cycle,technical characteristics,maturity and other indicators.This paper introduces the technical approaches of active manned spacecraft such as LiOH,molecular sieve and solid amine,analyzes its working principle,operation mode and engineering application in detail,compares its removal efficiency,equipment mass and operation power consumption,and analyzes the applicability of China's manned spaceflight multi mission mode in the future from the perspective of load quality change trend,The conclusion shows that solid amine technology is suitable for medi-um and long-term manned space missions,and has the trend of replacing molecular sieve technology.Under ideal condi-tions,solid amine or LiOH can be selected for short-term manned space missions according to mission requirements