The invention discloses a lamp, which comprises a shell, a lamp body and a lamp holder for holding the lamp body. The lamp holder is fixed in the shell through a locking device, wherein the locking device comprises a reset switch mechanism fixed inside the shell, and thrust force is applied to the reset switch mechanism or the lamp body so as to realize movement of the lamp body and the lamp holder relative to the shell. With a reasonable structure, convenient installation and replacement of a light source, the lamp effectively improves operation efficiency of installing and replacing the light source for workers. Therefore, the lamp is widely used in daily life of people.