The invention relates to a power transmission line vibration state monitoring device, in particular to a power transmission line vibration monitoring device. The problem that no mature equipment or devices exist for monitoring power transmission line vibration conditions at present is solved. The power transmission line vibration monitoring device is composed of a main control computer, a vibration measurement auxiliary machine, an inclination angle measurement auxiliary machine, a wind speed measurement auxiliary machine and a PC in a monitoring center, wherein the vibration measurement auxiliary machine transmits power transmission line vibration frequency signals to the main control computer, the inclination angle measurement auxiliary machine transmits signals of inclination angles at the two ends of a power transmission line to the main control computer, the wind speed measurement auxiliary machine transmits local wind speed signals to the main control computer, and the PC receives the corresponding signals sent by the main control computer and processes the received corresponding signals under the support of the corresponding software. According to the power transmission line vibration monitoring device, line vibration frequency and amplitude detection can be achieved, information collection, information transmission and information processing and analysis are integrated, and the power transmission line vibration conditions are comprehensively monitored.