The present utility model discloses a high voltage breaker mechanical property on-line live-line detection system. The system is provided to solve problems of the prior art that the on-line live-line detection of the mechanical property of a high voltage breaker can be realized. The system comprises a high voltage breaker (1) and a current and voltage waveform acquisition analyzer (5), a core-through magnet balance type zero magnetic flux Hall current sensor (3) is arranged on each phase of closing and opening coil circuit of a closing and opening coil control circuit (2) of the high voltage breaker (1), each core-through magnet balance type zero magnetic flux Hall current sensor (3) is electrically connected with the current and voltage waveform acquisition analyzer (5), and an A/D converter and a CPU are arranged inside the current and voltage waveform acquisition analyzer (5). The equipment is small and portable, the operation is simple, and on-site rapid analysis and judgment can be realized.