In order to provide the visible span of satellite for photoelectrical theodolite, we discuss the forecast method for the visible span of artificial satellites. Three important factors including height, shadow and sunlight are analyzed. The method has been used on a certain kind of photoelectrical theodolite.Choosing INTERCOSMOS and other three satellites as samples, experimental results indicate that this method can provide accurate visible span of satellite and fulfill the requirement precision of 103.629 ms. The method reduces the waiting time and advances the efficiency of operating staffs.