分体式探测光幕实现室内靶道弹丸初速测试时，探测光幕的灵敏度直接影响初速测量的精度。研究了线光源配接镜头式接收装置组成大面积三角形探测光幕的灵敏度分布，考虑光学镜头离轴效应和线光源随距离衰减现象，将探测光幕内不同位置处光照度等效到线光源处，假设光幕厚度均匀，弹长始终大于幕厚，弹丸遮挡探测光幕所形成的面积与当前区域光幕截面积之比等效为弹径与当前位置处光幕宽度之比。在4.8 m×2.4 m 三角形探测光幕上进行理论仿真与实弹试验验证，仿真分析与实弹试验结果一致，靠近镜头处灵敏度大，远离镜头处灵敏度小，且关键探测区域内模拟电压幅值标准差为0.05 V，均匀性符合测试要求。研究结果可为三角形探测光幕的工程设计提供参考。

When the split detection light screen is used to test projectile velocity of the indoor target trajectory, the sensitivity of detection light screen directly affects the accuracy of initial velocity measurement. The sensitivity distribution of a large-area triangular detection light screen formed by a line light source coupled with a lens-type receiving device was studied. Considering the off-axis effect of optical lens and the attenuation of line light source with the distance, the illuminance at different positions in the detection light screen was equivalent to the line light source. Assuming that the thickness of the light screen was uniform and the projectile length was always greater than the thickness of the screen, the ratio of the area formed by the projectile blocking the detection light screen to the cross-sectional area of the light screen in the current area was equivalent to the ratio of the projectile diameter to the width of the light screen at the current position. The theoretical simulation and live ammunition test verification were carried out on the 4.8 m×2.4 m triangular detection light screen. The simulation analysis results are consistent with the live ammunition test results. The sensitivity is higher near the lens and lower far away from the lens, and the standard deviation of the analog voltage amplitude in the key detection area was 0.05 V, from which the uniformity meets the test requirements. The research results can provide references for the engineering design of the triangular detection light screen.