Abstract: The technique of digital flexible assembly is one of the research directions in the field of aircraft manufacture in recent years. Aiming at aircraft parts positioning and joining, the technique and theory of digital flexible assembly based on laser tracking and positioning were studied. The laser tracking measurement system was developed through using the developing software package of the laser tracker. The frame and theory of mechanism motion and position device and servo control system were discussed. The servo control system of mechanism motion was carried out which could be used to control aircraft position. The integrating system of digital flexible assembly for aircraft parts joining was developed by using one graphics software package. Real-time simulation of aircraft parts joining based on laser tracking measurement was also achieved on the integrating system. This research work can be used for reference to the researching on the technique of digital flexible assembly in recent time.