In order to solve the problem of low accuracy of the fuselage of large aircraft in China, this paper studies　the docking method on the fuselage of a large aircraft. First of all, this paper selects and designs the docking datum of the fuselage and the docking station of the fuselage. Later, in the process of the fuselage docking, using a laser collimator, make the laser collimator light polymerization through artificial adjustment, and the desired data displayed on the digital display table, so as to adjust the body of the aeroplane. Again measuring actual coordinates of fuselage assembly datum using laser tracker, online measurement control system trims fuselage according to the actual coordinates measurement data to meet the requirements of the position of the fuselage and docking. Finally, according to the fine-tuning of the fuselage, the actual sitting value of the measured reference point and the square root of the sum of distance squares of the theoretical coordinates
are used to determine whether the fuselage butt meets the standard. The method of fuselage docking in this paper can reasonably control the deviation at the tolerance range. Through the study of large aircraft fuselage docking technology, laser tracker, laser collimator, online measurement software and servo drive device as the main body of online measurement control system, can greatly improve the accuracy of large aircraft fuselage docking.