This paper mainly discusse the design theory and various experiments of retro-reflector on Galileo navigation satellite.It is given out the calculated and experimental results of far field diffracting distribution of the laser retro-reflector.The work has been done on different corner angle aberrance and on retro-reflectors with and without film.Our researches indicate that:it is necessary to take aberration compensation into account in the corner-cube reflector design of navigation satellites as Galileo，and it is appropriate to design the reflecting surfaces without coating.