A phototherapy device (100), which comprises a phototherapy host (700) and a fitting device (800). The phototherapy host (700) comprises a base (110), a printed circuit board (130), a power supply unit (150), a light emitting unit (160), and an upper cover (170). The printed circuit board (130) and the base (110) are arranged as a group, and the printed circuit board (130) comprises a driving circuit and a conductive electrode group (140)； the power supply unit (150) may be selectively electrically connected to the conductive electrode group (140)； the light emitting unit is arranged in a group between the printed circuit board (130) and the base (110), and is electrically connected to the power supply unit (150) and the driving circuit； the upper cover is arranged in a group above the power supply unit (150) and covers the power supply unit (150), the conductive electrode group (140), the printed circuit board (130) and the light emitting unit (160)； the fitting device (800) comprises a tenon base (180), wherein the tenon base (180) is detachably combined with the base (110) by means of buckling, screwing or magnetic attraction so as to combine the fitting device (800) with the phototherapy host (700). Therefore, the light therapy device (100) has a light and thin volume and a simple structure for portable use, and may achieve the modular effect of replacing and changing the fitting device； meanwhile, the light therapy host (700) may also be used alone, and has flexibility in use.L'invention porte sur un dispositif de photothérapie (100), qui comprend un hôte de photothérapie (700) et un dispositif d'ajustement (800). L'hôte de photothérapie (700) comprend une base (110), une carte de circuit imprimé (130), une unité d'alimentation électrique (150), une unité électroluminescente (160), et un couvercle supérieur (170). La carte de circuit imprimé (130) et la base (110) sont agencées sous la forme d'un groupe, et la carte de circuit imprimé (130) comprend un circuit
