Satellite communication can provide over-the-horizon, large-capacity communication services. Nevertheless, there will be serious line-of-sight fading and significant multipath effect in urban areas, canyons, forests and other areas where the line of sight is seriously obscured, which will result in the degradation of network communication performance. Recently, an emerging technology―the Reconfigurable Intelligence Surface(RIS) is capable of dynamically altering wireless channels by flexibly controlling the electromagnetic properties of passive reflecting elements, providing a novel route for improving the quality of Low Earth Orbit(LEO) satellite communication. Based on the basic principles and advantages of RIS, the key technologies such as channel modeling, channel estimation, and beamforming in the RIS aided LEO satellite communication are discussed. Finally, the main challenges faced of RIS in practical applications are analyzed. This work can provide a reference for research in the field of RIS aided LEO satellite communication.