The present invention discloses a focus-adjustable lamp, provided with an illuminating mechanism on the top end thereof, wherein the illuminating mechanism comprises a light-emitting element, a shield body shielding the outer side of the light-emitting element, a heat dissipating member closely matched with the light-emitting element, and a cover body located on the top end of the illuminating mechanism, the illuminating mechanism is further provided with a light-converging cylinder rotationally sleeving the outer side of the shield body, and the light-converging cylinder is capable of rotating back and forth along a circumferential direction of the shield body to adjust the size of a light spot projected by the light-emitting element on the ground.