Abstract: The radiative transfer softwares such as MODTRAN or 6S can be directly used to compute remote sensing radiances of the sensors which illuminated by the sun.But lunar irradiance must be integrated in the computation for the glimmer sensors which detect the lunar radiation reflected by the objects.The lunar surface albedo and extraterrestrial solar irradiance already been known and published were used to calculate the lunar irradiance.Till now only 6S can easily include the lunar irradiance in radiative transfer computation.By description of how to compute lunar irradiance in detail then obtained extraterrestrial moon surface irradiance in the range of 0.250μm~1.500μm.