Based on the geometric relation among orbital target,observation satellite,the earth,the sun,and the moon,an optical visibility determination model between observation satellite and orbital target is derived by taking into account of the earth background,the earth light,the sunlight,the earth shadow and the moonlight,and then a visibility prediction method for space-based optic observation is also given.The simulation result shows that the earth background and the earth light are the primary factors which influence space-based optic observation.On the aspect of observation time,it has limited efficiency for low earth orbit target space-based observation,and good efficiency for high earth orbit observation.