The control target of stray light is deduced based on solar power transmission and the allowable stray light radiance at the exit pupil.Two schemes used to eliminate direct radiation were present,one way is setting primary baffle and secondary baffle,the other way is only setting primary baffle and Lyot stop near the exit pupil.Theoretial analysis indicates that by setting the secondary baffle the first scheme will increase the obscuration ratio,and by setting the Lyot stop near the exit pupil the second one will appear vignetting.Since the requirements of receiving /emission efficiency for optical antenna are very high,it′s also needs to take into account the energy in the design process.The receiving /emission efficiency and stray light suppression level of the two scheme were analyzed to some cassegrain optical antenna.The emission efficiency and stray light suppression level of the second scheme is better than the first,but the receiving efficiency of edge field is slight lower.Finally the second way was used to control the stray light of the optical antenna prototype,and its stray light level was tested.The results show the extinction ratio are lower than -40 dB when the range of off-field angle is from 1° to 20°,it meets the requirement.