The embodiment of the utility model discloses phototherapy device, this phototherapy device include the transparent diffusion module of circuit board, light source and light, have set up the light source on circuit board 's the interarea, and circuit board is used for providing working power supply for the light source for the light source can be to keeping away from the direction of interarea jets out light. The diffusion module setting be in one side of interarea orientation, from this, the light that jets out from the light source can pass through earlier before reacing the phototherapy region the diffusion module, the diffusion module is the transparent material of light, and should spread the module can spread the light that passes self, makes to work as the light that the light source jetted out is followed angle of emergence when the diffusion module jets out is greater than the light incidence that the light source jetted out the angle of incidence of diffusion module. The diffusion of light is jetted out through diffusion pair of module light source for it is more even that the light source jets out the plain noodles of light, will be difficult to improve user experience the regional facula that assembles that forms of phototherapy.