Abstract: The thermal control fluid loop system technology scheme of manned spaceship was introduced,including system configure,flow chart,operating model,main technical status,and etc.All of the fluid loop experiment cases and related results were listed.Test data shows that fluid loop system has excellent temperature adjustment and adaptation ability.Further analysis of the heat transfer capability was carried out on heat exchange devices such as thermal radiator,air condenser,cold plate,and middle heat exchanger.Besides,the accumulator capability was also proved under the extreme low temperature case.The fluctuant problem of pump′s pressure head caused by gas released from fluid under extreme low pressure was also discussed.Finally,some suggestions on future fluid loop system improvement were presented.