The invention relates to the technical field of down lamps, in particular to a down lamp with components capable of being commonly used and replaced. The down lamp comprises a face ring base which is connected with a lamp body module and a reflection cup in a matched mode. The cross section of an inner cavity of the face ring base is circular. The cross section of the lamp body module is circular. An annular edge is arranged on the lower portion of the lamp body module. The face ring base is provided with an upper rim and a lower rim. The upper portion of the inner wall of the face ring base is correspondingly provided with at least two first leaf springs. A first arch-shaped protrusion is formed on each first leaf spring. All the first arch-shaped protrusions are located in the same horizontal plane. The outer diameter of the annular edge is smaller than the inner diameter of the lower rim and larger than the inner diameter of the upper rim. The annular edge is clamped between the first arch-shaped protrusions and the upper rim. According to the down lamp, replacement between the face ring base and the lamp body module can be achieved according to changes of environments and mounting conditions, and therefore the product cost is lowered; meanwhile, using flexibility is improved.