Abstract: A ship-borne searchlight comprising a lamp housing, a reversible motor installed on the lamp housing, a movable cover pivotally connected to the lamp housing and a lamp mounted on back side of the movable cover, wherein the movable cover has a sector block formed on its back side and a ring gear further formed on lower circumference of the sector block to engage a driving gear inside the lamp housing, so that by controlling the reversible motor the driving gear shall rotate in clockwise or counter clockwise direction to enable a movement of open-up or close-down of the movable cover relative to the lamp housing to vary the direction of light beam of the lamp; particularly, when the ship-borne searchlight is not in use, the lamp shall be kept inside the lamp housing to save space taken up by the searchlight.