A light source module (10) includes a substrate (100), a light emitting device (120), an encapsulation structure (140), and an optical pattern (160). The light emitting device (120) is disposed on a surface (100s) of the substrate (100). The encapsulation structure (140) is disposed on the surface (100s) of the substrate (100) and covers the light emitting device (120). The optical pattern (160) is covered by the encapsulation structure (140) and overlaps the light emitting device (120). The optical pattern (160) has characteristics of partial penetration and partial reflection and is provided with a first active zone (AZ1) and a second active zone (AZ2). The first active zone (AZ1) and the second active zone (AZ2) are arranged in a direction parallel to the surface (100s) of the substrate (100). The first active zone (AZ1) and the second active zone (AZ2) of the optical pattern (160) respectively has a first transmittance and a second transmittance, and the first transmittance is different from the second transmittance.