Aiming at the heavy measurement task in the process of fighter manufacture and assemble, as well as the problems of heavy equipment and low efficiency in the existing methods of boresight for fighter plane weapon, a new method of boresight for fighter plane weapon based on the measurement principle of binocular vision is proposed. A photoelectric target composed of infrared LEDs is designed, which is connected with calibration station of the fighter through the adapter. The binocular cameras take pictures of all photoelectric targets, and then obtains the three-dimensional coordinates of the LED points. Then, the relative attitude parameters between the binocular cameras and each photoelectric target will be calculated by using the principle of space coordinate transformation based on least square method. And the horizontal/vertical deviation angles of the stations axes to be measured relative to the axis of the fighter’s reference station can be finally obtained by combining the coordinate system transfer, and the boresight operation will be completed. Based on the principle of boresight, a 3D simulation environment is built, the possible error sources in the process of boresight are analyzed, and the boresight algorithm is simulated using Monte Carlo method. The simulation results show that the  cameras calibration error has the greatest impact on the measurement accuracy of horizontal/vertical deviation angles, with the standard deviation of 0.0397° and 0.0268°, respectively. This proposed method can be applied to the boresight for fighter plane weapons, which can also improve the work efficiency and reliability in the process of assembly and measurement.