In response to the issue of continuously increasing short-circuit breaking voltage in photovoltaic DC circuit breakers, this study focuses on DC molded case circuit breakers. First, through theoretical analysis, it was determined that the arc blowing magnetic field under high-voltage conditions affects the arc quenching performance of molded case circuit breakers. Next, using Maxwell electromagnetic simulation software, different arc quenching systems were analyzed, and the magnetic blowing force experienced by each segment of the arc under various arc quenching systems was obtained. The corresponding magnetic blowing force density was derived from the magnetic blowing force experienced by each segment of the arc. By comparing the force densities and optimal values of different arc quenching systems, it was found that the optimized magnetic blowing device is more conducive to the arc entering the arc quenching grid. This provides a reference for subsequent research on optimizing the breaking performance of photovoltaic DC circuit breakers.