As an emerging auxiliary technology for orthodontic treatment，photobiomodulation therapy （PBMT）has been gradually promoted and used in clinical practice. Most studies have found that it can play a positive role in accelerating orthodontic tooth movement，reducing pain and decreasing orthodontically induced inflammatory root resorption，but its mechanism is not completely clear. This article reviews the progress of PBMT in orthodontic research at home and abroad in recent years，and further elaborates the specific mechanism and research status of PBMT on orthodontic tooth movement，pain and root resorption.