Abstract: The invention provides a waterproof lamp, which comprises a waterproof lamp body, wherein a switch is arranged on the waterproof lamp body, a waterproof switch structure is arranged at the switch, and the switch is arranged in an inner cavity of the waterproof switch structure; the invention also relates to a working method for the waterproof lamp. The waterproof lamp is provided with the waterproof switch structure at the switch, the waterproof switch structure comprises a waterproof sleeve and a fixing sleeve, and the structures and connection mode of the waterproof sleeve, the fixing sleeve and the waterproof lamp body ensure the sealing of the waterproof lamp at the switch, so that the waterproof lamp can be used underwater for a long time; the working method of the waterproof lamp can avoid oxidation and rusting when the waterproof lamp is used underwater, and prolong its service life.