Depression is a kind of mental disorder with high prevalence rate, easy relapse and high suicide rate, which can easily lead to cognitive impairment and other problems. Phototherapy, with its advantages of noninvasive, less side effects and quick curative effect, has attracted wide attention, which provides a new possibility for regulating the biorhythm and sleep disorders of depression. Light signals are projected through retinal ganglion cells to depressed brain areas to participate in non-visual imaging functions, activating nerve cell activity, secreting neurotransmitters to induce physiological changes in neural pathways, and regulating circadian rhythms, mood, and sleep in the biological organism to improve depressive behavior. The most common forms of light therapy include bright light therapy, blue light therapy and near infrared light therapy. The choice and use of different light sources can have different effects on the therapeutic outcome, and their wavelength, dose and optimal mode of action are closely related to the therapeutic outcome. The results also suggest that the use of low intensity beneficial wavelengths of blue light can have the same antidepressant effect as high intensity bright light therapy, but the best mode of application of phototherapy is still controversial. In order to promote the application of phototherapy in the field of life science and clinical practice, a large number of studies on optical parameters in clinical and animal models are still needed. This paper will summarize the current therapeutic targets of light therapy in depression-related brain regions and downstream neural circuits, explore the mechanisms of action of different spectra and their therapeutic parameters, discover the advantages of their light sources and suitable therapeutic parameters, and propose the problems of phototherapy, such as the optimal light parameters, the universality of different populations, and the safety issues arising from unsuitable light sources, which are still to be solved. As phototherapy continues to be explored in depth, the selection of optimal phototherapy pathways, the screening of optimal light parameters, and the combination of other classical therapeutic methods will provide references for experimental studies and clinical applications of phototherapy against depression and produce breakthroughs in the treatment of depression.