The invention relates to an underground staff detecting instrument and a staff 
monitoring system based on miner light weak 
light detection. The detecting instrument is provided with a 
light detector with high sensitivity, a 
light detector with low sensitivity, and an electronic control module which is electrically connected with the two light detectors; a comparing unit and a storing unit are arranged in the electronic control module; a preset illumination 
lower limit value is stored in the storing unit; the comparing unit is used for comparing a practical illumination value detected by the 
light detector with low sensitivity with the illumination 
lower limit value; when the practical illumination value detected by the light 
detector with low sensitivity reaches or exceeds the illumination 
lower limit value, the electronic control module controls the light 
detector with high sensitivity to stop working; and the 
system comprises a plurality of detecting instruments, a plurality of transmission substations and a management 
master station which are connected and communicated pairwise. According to the underground staff detecting instrument and the staff 
monitoring system based on miner light weak 
light detection, detection and alarm for miner light weak light can be realized, and whether people are in a blasting area or not can be judged under the condition without adding personal operation equipment of miners, so that burdens of the miners can be reduced, and the difficulty in managing the equipment is reduced.