In order to calculate the temperature and infrared radiation characteristics of space target,it is necessary to master the distribution and variation regularity of the orbit external thermal flux on target.Analyzing the energy exchange relationship between the inside and outside of the space target in orbit,the numerical simulation method was used to simulate the temperature and infrared of a cone-shaped space target,and the influence of various parameters on the calculation results was quantitatively analyzed.The results show that the angle β between sunlight and orbital plane has a significant effect on the temperature and infrared variation of space target;the calculation results are more sensitive to the change of β when β is larger.Considering the change of the earth albedo with latitude,the temperature and the infrared radiation intensity of 8～14 μm reduced by 1.73 ℃ and 0.27 W/sr respectively.The variation of albedo cannot be ignored when calculating the characteristics of space target accurately.