The invention relates to the technical field of automobiles, in particular to an automobile high-low beam automatic switching system. The luminous intensity detected by an automobile front luminous intensity detecting device can be switched by an A/D switching module and then is transmitted to a single-chip microcomputer controller by the A/D switching module, the single-chip microcomputer controller turns on the automobile high beam and turns off the automobile low beam simultaneously or turns off the automobile high beam and turns on the automobile low beam simultaneously through an actuator, and an automatic detecting device can conduct automatic detecting on the A/D switching module, the single-chip microcomputer controller and the actuator; and according to the automobile high-low beam automatic switching system, turning-on and turning-off of the high beam and the low beam of an automobile can be automatically adjusted according to the luminous intensity in front of the automobile, and the safety of driving of the automobile is improved. Moreover, the automobile high-low beam automatic switching system is reasonable in design, convenient and reliable to use and suitable for being promoted to be used.