In order to meet the requirement of further development of large scale grid, a new kind of high voltage and large capacity vacuum circuit breaker is presented. This new equipment adopts series-parallel technology of 40.5 kV circuit breaker module to make its rated working voltage and current upgrade to 126 kV and 5 000 A respectively, and short-circuit breaking current reach up to 80 kA. Through the tightly coupled split reactor’s automatic current sharing/current limiting technology and dynamic uniform voltage technology, the reliability of equipment is improved. The installation and trial operation of the circuit breaker machine are completed, the data measurement of the running equipment is accomplished, including current, temperature, and magnetic flux leakage value. Relevant test data and the stable operation of the circuit breaker during the trial operation verify the validity of the circuit breaker. The whole work provides a good idea for the future development of vacuum circuit breaker.