摘要： The luminosity of lightning channel is closely related to the lightning current. In the present paper, a lightning channel luminosity detection system (LCLDS), comprising of an avalanche photodiode module, a neutral density ?lter, an extension tube and an adjustable horizontal slit, is assembled. By using the impulse current generator, lightning impulse currents with di?erent amplitudes and also di?erent waveforms were produced in a 15-mm open-air gap between two graphite-rod electrodes. The luminosity and the current of discharge channel were measured synchronously. The experiments looking into the in?uencing factors of luminosity measurement, including the alignment of the silt and the slit width, were carried out. Obtained results show that the slit opening center of LCLDS should be aligned to the center of the discharge gap. Otherwise, in the case of improper alignment, the measured luminosity waveforms associated with the same injected current might be quite dif- ferent in the amplitudes as well as in the waveforms. Moreover, the peak luminosity increases linearly with increasing slit width, whereas the luminosity waveforms are practically una?ected, implying that, in the prac- tical application, the slit width can be adjusted to alter the luminosity signal output according to the actual need. Obtained results here can establish the foundation to develop the correlation between the current and the corresponding luminosity in the future.