A car lamp low beam and high beam light switching device, comprising a light screen, an electromagnetic actuator, and a bracket fixed on the lamp body, wherein: the electromagnetic actuator is a rotary electromagnetic actuator comprising a shell, a rotor, a stator, a rotating shaft and an end cover, the rotary electromagnetic actuator being fixedly connected to the bracket through the shell and connectable to the lamp body through the bracket, and used for driving the light screen of the car lamp low beam and high beam light switching device, characterized in that: a stator winding is arranged on the stator, and the stator and the stator winding are fixedly mounted in the shell to form a pair of arc-shaped stator magnetic poles on which electric excitation can be applied; the rotor, which is an arc-shaped permanent magnet, is fixed on the rotating shaft and is located in a magnetic field space formed by the arc-shaped magnetic poles of the stator; and the rotor is matched with the arc-shaped stator magnetic poles to form a closed magnetic circuit with an air gap; a swing bar extending along a radial direction of the rotating shaft is connected to each of the two ends of the rotating shaft respectively; the light screen of the car lamp low beam and high beam light switching device is fixedly connected on the swing bars disposed at the two ends of the rotating shaft; and a swing angle of the light screen is identical with a rotating angle of the rotor; the permanent magnet of the rotor is integrally injection-molded with the rotating shaft and the swing bars; each end of the rotating shaft of the electromagnetic actuator is respectively connected with one swing bar extending along the radial direction of the rotating shaft; the light screen is fixedly connected to the swing bar, and placed on the light axial line of the lamp associated with the car lamp low beam and high beam light switching device; an included angle between the light screen and the light axial line can be changed along with the rotating angle of the rotor; an outline of the light screen is projected on a road to form a light model of the low beam and high beam light, the light model being changed along with the rotation of the rotor between the low beam and high beam light model. a stator winding is arranged on the stator, and the stator and the stator winding are fixedly mounted in the shell to form a pair of arc-shaped stator magnetic poles on which electric excitation can be applied; the rotor, which is an arc-shaped permanent magnet, is fixed on the rotating shaft and is located in a magnetic field space formed by the arc-shaped magnetic poles of the stator; and the rotor is matched with the arc-shaped stator magnetic poles to form a closed magnetic circuit with an air gap; a swing bar extending along a radial direction of the rotating shaft is connected to each of the two ends of the rotating shaft respectively; the light screen of the car lamp low beam and high beam light switching device is fixedly connected on the swing bars disposed at the two ends of the rotating shaft; and a swing angle of the light screen is identical with a rotating angle of the rotor; the permanent magnet of the rotor is integrally injection-molded with the rotating shaft and the swing bars; each end of the rotating shaft of the electromagnetic actuator is respectively connected with one swing bar extending along the radial direction of the rotating shaft; the light screen is fixedly connected to the swing bar, and placed on the light axial line of the lamp associated with the car lamp low beam and high beam light switching device; an included angle between the light screen and the light axial line can be changed along with the rotating angle of the rotor; an outline of the light screen is projected on a road to form a light model of the low beam and high beam light, the light model being changed along with the rotation of the rotor between the low beam and high beam light model.