The target coordinates of the projectile have always been the parameters that are often measured in the field of external ballistic testing of barrel weapons. Aiming at the problems of complex system and heavy main detector of the existing six light screens array sky screen vertical target, an integrated double-N-type six light screens vertical target measurement scheme is proposed. Three detection light screens are integrated in an optical lens of each main detector, and two main detectors form two N-type three light screens detection arrays in the air. When the projectile passes through six detection light screens in turn, the corresponding two main detectors are equipped with the circuit of three light screens sky screen target outputs six projectile signals in turn. The projectile signals are collected by the data acquisitioninstrument, and the collected projectile signals are processed by the projectile signal processing algorithm to obtain the time value of the projectile passing through the six detection light screens. Further, the target coordinates value of the projectile are calculated through the corresponding detection light screen parameters and target distance parameters. The measurement error of the system's target coordinate is analyzed, and the accuracy of the system's projectile target coordinate measurement is verified by two different kinds of caliber live ammunition tests.