Abstract: Aiming at the problem of vertical target coordinate measurement when two projectors were touching the target at the same time, a two-target identification method of circular array photoelectric detection system was proposed. A circular detection array was formed by using photodetectors, and three fan-shaped linear lasers with all luminescence angles of 60° were uniformly arranged on circular detection array to form a detection light curtain. When the two projectiles passed through detection light screen at the same time, six projectiles would be generated on the circular detection array. The central position of the six projectiles would be identified through the signal processing circuit. Finally, the target coordinates of two projectiles would be calculated by system projectile hitting coordinate measurement formula. On the basis of the theory of system measurement, the coordinate measurement model of the projectile hitting target was established, and the coordinate measurement error was analyzed and simulated. The simulation results show that the maximum standard deviation of the X coordinate measurement error is 2.7 mm and the maximum standard deviation of the Y coordinate measurement error is 0.6 mm when the target surface is 1 m×1 m. The experimental results show that the standard deviation of X coordinate measurement error is 2.22 mm and Y coordinate measurement error is 1.98 mm when the target surface is 1 m×1 m. Therefore, the system proposed can effectively measure the target coordinates of double projectors with a projectile diameter of 4.5 mm or above.