Abstract: With the acceleration of global urbanization, the intensity and coverage of artificial light at night (ALAN) are increasing, and its service duration is obviously prolonged. ALAN exposure is not only related to the occurrence and development of cardiovascular, metabolic, sleep, myopia, and mental diseases, but also may induce cancer. Previous studies have focused on the health effects of outdoor ALAN, but people spend more than 80% of their lives indoors, hence it is of great significance to understand the relationship between indoor ALAN and population health to create a healthy indoor environment and protect the health of the population.