Abstract: A device for controlling high beam and low beam of a headlight includes a fixing plate formed with a recess and bored with two pin holes, two curved slots and a sliding slot. A valve base secured on the fixing plate is installed therein with an electromagnetic valve having a valve rod inserted in the interior and a spring fitted on the valve rod. A positioning seat is mounted on the valve rod and has one side provided with a connecting rod to be inserted through two mutually overlapped ends of two connecting plates and in the sliding slot of the fixing plate. Two boards are oppositely and pivotally assembled on the fixing plate, having their lower sides respectively and pivotally connected with the upper ends of the two connecting plates by insert pins, which are then inserted in the two curved slots of the fixing plate.