To address the issue of decreased reliability in power transmission caused by the incapability of existing parallel protection gaps to actively extinguish arcs，a method utilizing the power-flow current flowing through coil to generate a magnetic field，and employing electromagnetic force to drive a piston to compress air and jet high-speed airflow for arc extinction is proposed. Consequently，a double-ended electromagnetic air-blast segmented arc-extinguishing device is designed. Based on the theory of magnetohydrodynamic，the theoretical model is built by using finite element simulation software，and the arc-extinction process of the device is simulated and analyzed. The results show that the arc-extinguishing airflow maximum speed is up to 330 m/s. Arc-extinguishing airflow rapidly act on the arc from the upper and lower ends，under the action of high-speed airflow，the arc gradually thinned out to break the dynamic equilibrium. The arc column temperature decreases to 2 000 K within 3 ms，and the arc channel pinch off，so as to realize the ″no arc channel″. The arc-extinguishing time is only 9% of the time before the installation of the device. The device can greatly shorten the arc-extinguishing time，and improve the reliability of the power supply system.