A light source module including at least one optical film and a light source unit is provided. The light source unit is disposed under the at least one optical film, and a space is formed between the light source unit and the at least one optical film. The light source unit includes a plurality of light emitting elements and a plurality of secondary lenses. The light emitting elements are arranged along a direction parallel to the at least one optical film. The secondary lenses are correspondingly disposed on the light emitting elements and each of the secondary lenses has a patterned reflective layer. Each of the secondary lenses has a light hole radius R, a distance between a distribution range of the patterned reflective layer and a bottom of the corresponding secondary lenses is H, and the distribution range of the patterned reflective layer satisfies 1/R