In order to increase OSNR (Optical Signal Noise Ratio, OSNR) of QSFP+ module, a multiplexing algorithm is proposed. Firstly, the development of optical module and the characteristics of QSFP+ module are illustrated; Secondly, the realization steps of the multiplexing algorithm is provided; Thirdly, this algorithm is applied in QSFP+ module and the corresponding circuit of host board is designed and the experimental result shows that multiplexing algorithm is able to increase OSNR 2 dB.