The DC miniature circuit breaker is the most critical protection and control equipment for low-voltage power distribution systems. Its speed of breaking and extinguishing arcs has an important impact on the system and itself. On the basis of the current research on polar magnetic blow-out, the author proposes the non-polar magnetic blow-out scheme, which solves the problem of the positive and reverse use of miniature circuit breakers. Additionally, the author studies the influence of different magnetic field intensities on arc extinguishing of non-polar DC miniature circuit breakers at the current level of 32A. The results show that the non-polar magnetic blow-off has a good effect on the positive and reverse use of circuit breakers. Under four different magnetic field intensities, the arc-extinguishing time is the shortest at the intensity of two 120mT magnetic fields, which improves the use efficiency of miniature circuit breakers and prolongs the electrical life of DC circuit breakers.