During the sun′s sweep of the field of view of solar radiation monitor, varying function of incident angle and temperature response of radiometer receiver cavity is studied. Calibration of time-varying incident angle for solar radiation monitor is also discussed. The absolute radiometer of solar radiation monitor detects small changes of the radiation through electrical calibration. We take radiation power of these small changes as a factor to revise solar radiation. FY-3 satellite has measured more than 2×104 sets of data in the past two years. The data is amended through the changes of observation angle and the obtained value of solar constant is 1368±4 W/m2, and the uncertainty is 0.3%. This result is in areement well with the value of 1367±7 W/m2 which is recommended by World Meteorological Organization and data measured on other satellites in the same period.