Abstract: In view of the large mass of moving parts and low speed of the electromagnetic repulsion mechanism（ERM）for the 4 kV/6 kA vacuum circuit breaker, a number of small ERM were used in parallel to replace the single mechanism.The breaking process of hybrid dc vacuum breaker was briefly described. The number of parallel mechanisms was discussed according to the mass of moving part and working pressure of the contact under different short current. The layout of mechanisms and the interaction of each mechanism during opening were studied, and the displacement characteristic and current dispersion of the mechanisms were discussed considering the possible differences. The experimental results showed good agreement with the simulation, and the distance of 5.5 mm can be achieved within 2 ms which indicates the displacement characteristics of mechanisms in parallel is better than that of the original single mechanism. Besides that, the vibration and shock of the vacuum circuit breaker can be effectively reduced due to the lower energy consumption of the opening mechanism.