Abstract: We establish a method to eliminate the influence of solar declination on optical characteristics of a GEO (Geostationary-Orbit) satellite, based on the spatial geometric relations between the satellite, the sun and the observatory. Under different solar declinations, a box-shaped 3-axis stabilized GEO satellite is represented by a scaled model in our photometric simulation. With the simulation method corrective results are presented to eliminate the influence of solar declination on the satellite luminosities and light curves at a series of values of orbital phase angle. The results are significant for deriving physical and structural properties of space debris.