The invention discloses a capacitive voltage transformer and a transmission characteristic analysis system and an operation method thereof. A local signal sampling device, a data analysis and recording device and a capacitive voltage transformer are comprised. Connecting pieces between the low voltage terminal of an electromagnetic unit of the capacitive voltage transformer and the low voltage terminal of a capacitor divider and between the low voltage terminal of the electromagnetic unit and a ground terminal are connected in series with a current collecting device respectively. The outputend of the current collecting device is connected with the input end of the local signal sampling device. The output end of the local signal sampling device is connected with the input end of the data analysis and recording device. The data analysis and recording device is used to calculate the actual harmonic voltage of the primary side of CVT according to received capacitive current combined with the capacitive reactance of a CVT capacitor. The analysis system provided by the invention can realize continuous monitoring and analysis of the true harmonic voltage content of a primary side power grid through CVT, and has high accuracy.