Light-emitting diode (LED)is a semiconductor material that converts electrical energy into light energy. With the constant upgrading of LED technology, its application range is also extended from the traditional lighting field. In recent years, LED has received more and more attention in clinical application and experimental study, especially in the areas of skin diseases, arthritis, osteoporosis, wound healing and repair, anti-infection and immune regulation. This paper mainly reviews the study and application of LED red light in different clinical diseases.