Abstract:A fuzzy analysis method is presented to determine thermal comfort temperature in manned spacecraft cabin. On the base of analyzing the influence of astronaut activity level, relative humidity and set temperature on thermal comfort, the set temperature of air-condition system is determined by use of fuzzy theory, and the polling list of temperature is given. The results can direct the astronauts to set the control temperature of air-condition system according to practical condition, and provide theoretical basis for the automatic control design of air~condition system with variable set temperature.