A light source module including: at least one lighting seat bodies equipped with light-emitting diodes, the light-emitting diodes being connected with a lighting circuit, whereby after the lighting circuit is closed, the light-emitting diodes are driven and lighted; and a light guide medium, at least one face of the light guide medium being defined as an incident face right facing light-projecting faces of the light-emitting diodes. A back face of the light guide medium is printed with multiple reflective sections. The light coming into the light guide medium is reflected by the reflective sections to a front face of the light guide medium and goes out from the front face.