Repeated positioning accuracy is an important performance index of some moving object，which is relatively simple measuring method is to use a ruler or tape measure to measure directly and manually，which is difficult to ensure measurement accuracy，and the measurement efficiency is lower，the consistency of multiple measurements is not good，but the cost is lower。Another measurement method is to use an expensive coordinate measuring instrument，the accuracy of this measurement method is very high，and the consistency of repeated measurement is good，but the cost is very high。According to the advantages and disadvantages of the above two measurement methods，the motion model of the object is establish at first，then the mathematical model which is easy to understand and realize is abstracted from the motion model，finally，based on the mathematical model，by means of electronic technology，the displacement laser sensor is selected as the measurement distance means，and the repeated positioning accuracy detection system is designed。This system is simple to operate and the measurement accuracy is higher and has a low cost。