The polarization of optical signal in optical fiber composite overhead ground wires(OPGW) will change due to wind vibration, which leads to the degradation of the system performance. In order to understand the effect of wind vibration on the polarization state in OPGW, and polarization state of OPGW changes under different swing conditions are simulated by experiments. Based on the measured data, the paper analyzes the rule of the polarization state change and concludes how it influences the coherent optical communication system, and gives the calculation basis for compensation algorithm in coherent optical communication system. The experimental results show that the rotation speed of signal polarization caused by the two kinds of wind vibration is 700 rad/s and 7 krad/s respectively, and the receiver needs to compensate for this magnitude velocity of the polarization state change.