In projectile velocity test, skyscreens non-working status will lead to measurement bias, so skyscreens calibration before test is important. In the paper, the calibration system circuit was designed, the scene that projectile getting through the light curtain of the skyscreens was simulated by controlling the bright white LED light source. The results show that the pulse width and interval of two channels of excitation signals output by the system are basically consistent with that of induced signal collected by photoelectric sensor, resulting in correct calibration for skyscreens system. This provides an effective way for skyscreens calibration.