The line side module CFP2-DCO has important and extensive application in 4G/5G network construct. Optical signal-to-noise ratio (OSNR) is an important parameter to evaluate the performance of the CFP2-DCO. The interference of polarization mode dispersion(PMD) and chromatic dispersion (CD) had important influence on the OSNR performance, the degradation of the OSNR induced by the PMD and CD is the OSNR penalty of PMD and CD. Different kinds of OSNR measurement methods are discussed. An automatic measurement platform on OSNR and PMD/CD penalty of the CFP2-DCO is introduced for the lab test requirement of communication equipment manufacturer. The OSNR and the PMD/CD penalty of the CFP2-DCO is tested using this platform. The PMD/CD penalty on the OSNR and the PMD/CD versus OSNR relation curve is further measured. The test results show that the OSNR requirement of the telecommunication system will be increased with the PMD/CD interference increasing. So, the PMD/CD interference should be decreased to optimize the system performance.