In order to study the partial discharge pulse current test method of large capacity capacitor for UHV, the equivalent model of partial discharge of capacitor electrical weakness is analyzed and the reasons for the difficulty of detecting partial discharge in high voltage large capacity capacitor are analyzed by the simulation. A broadband high gain through CT type detection impedance is designed for UHV capacitor pertinently. Through the contrast test of pulse current method and ultrasonic method and background noise test of pulse current method, the feasibility of pulse current method to detect partial discharge of capacitor used in UHV is verified, thus enriching the UHV capacitor random handover test methods and ensuring the reliability of operating capacitor quality. This work is supported by Science and Technology Project of State Grid Corporation of China “Key Technology Research of the Optimization of UHVAC Main Equipment Test Methods”.