A light source module comprises a substrate at an inner side of a fixing plate, a heat dissipation plate at an inner side of the substrate, a fixing base at an inner side of the heat dissipation plate, a positive and a negative electrode elastic element. The substrate is connected with an illuminate element and formed with a positive and a negative electrode connecting portion for respectively connecting to the positive and negative electrodes of the illuminate element. The positive and negative electrode elastic elements are sleeved at the fixing base and respectively formed with a positive and a negative electrode pin to connect to the positive and negative electrode connecting portions. Accordingly, assembly is easier and more convenient, bad connection or short circuit does not occur, and inner resistance and the power consumption are decreased.