An illuminating device includes a housing, a light-emitting assembly and a driver, wherein the housing includes a first and second cavity and a partition plate, wherein an open end in the first and second cavity may accommodate the light-emitting assembly and the driver, respectively. A lens and a driver housing further respectively mounted thereon wherein the lens and driver housing includes a first supporting leg and a second supporting leg, respectively. The second supporting leg is engaged with a first stop portion formed on an inner wall of the housing, wherein the first supporting leg extends in a through hole in the partition plate to move between a first and a second position deviating circumferentially from the first position, the first supporting leg is locked at the first position between the partition plate and a second stop portion formed in an inner wall of the housing.