The invention discloses a DC arc extinguishing switch relay, comprising a lower housing, an upper housing, an electromagnetic driving coil, a contact bridge retaining frame, an U-shaped magnet and a big contact. The DC arc extinguishing switch relay is characterized in that the lower housing of the DC arc extinguishing switch relay, an upper housing of the DC arc extinguishing switch relay and the contact bridge retaining frame adopt plastic to perform one time injection molding; the contact bridge and the big contact are driven to be contacted through the contact bridge retaining frame under a magnetic force, and the contact bridge is broken away from the big contact through a rebounding force; one side of the big contact is provided with the U-shaped magnet, which forms an enclosing type arc extinguishing magnetic field in a working area of the contact bridge and the big contact; a sealing rubber ring is pressed to achieve the sealing effect, and the reinforcement is performed through smearing sealing glue or welding by an ultrasonic welding machine. Through above arrangement, the performance of blowing out art extinguishing by the magnetic is dramatically improved, and the big size of the magnetic has obvious heat radiation effect in the temperature of the art extinguishing zone, which control the damage on the contactor by the arc and prolongs the service life. Furthermore, the DC arc extinguishing switch relay can be widely applied in the electric automobile engineering power system.