Abstract: We describe the technology of the orbit determination for the Lunar satellite,analyze and solve the key problems.The system of the precision orbit determination is verified and testified depending on the observation data of the SMART-1 Lunar satellite.The orbit determination can be obtained with an accuracy of 100 meters for three-day-arc data.During the CE-1 mission,the result of the orbit determination is accurate.The satellite inject the mission orbit successfully.There is only one middle course correction during the transfer orbit phase although three times of correction are prepared.The fuel is saved for the satellite.Compared with the ephemeris of CE-1 satellite from GEODYN II,the accuracy of the orbit determination is about 100 meters level for whole course and tens of meters for orbiting Lunar phase.It is shown that the technology described in the paper is correct,and the key problem is solved effectively.The system can satisfy the requirement of CE-1 mission.