A manufacturing method of a light source module includes the following steps. Firstly, a light emitting diode die is installed on a supporting base. Then, an electric connection between the light emitting diode die and the supporting base is established. Then, a protective glue is formed on the light emitting diode die and the supporting base. Afterwards, the supporting base is cut to produce the light source module. Since the supporting plate is not employed, the supporting plate removing process and the boning process of the conventional technology are omitted. Consequently, the manufacturing method of the present invention is effective to enhance the production quality of the light source module.