Abstract: In order to reduce the accident rate and protect the vision and personal safety of the workers, a good light environment must be ensured in coal mine underground. Coal miners are in near-dark coal mines for a long time, especially in complex environment of fully mechanized mining face at the same time to operate a variety of machines, it is very important for the miners’ to obtain visual information from the visual and lighting environment. Different illuminance levels were used as variables, and two physiological signals of heart rate variability and blood pressure were selected as analysis indexes to study the effect of different illuminance levels on human physiology. The results show that: the illuminance level is 20 lx to 100 lx, heart rate （ＨＲ）, mean heart beat cycle are reduced in the different degrees, and as the illuminance level increases to 300 lx, the two indexes gradually tend to the measured individual values, but when the illuminance is higher, the two indicators began to change; too high or too low illuminance level will have different degree influence, when the illuminance level is 200 lx to 300 lx, it reaches the optimal physiological state of the human body; the relationship between the physiological signal and illuminance level is quantified by establishing regression equation.