A rotary lamp holder comprises a housing having a first longitudinal end and a second longitudinal end, the first longitudinal having an opening, a motor stator disposed around the inner circumference of the housing, a rotating shaft and rotatably mounted in the housing, the rotating shaft defining a cavity in communication with the opening of the first longitudinal end, a motor rotor fixed to the rotating shaft and coaxially disposed with the motor stator, a lamp cover bracket rotatably mounted relative to the housing and extending out of the first longitudinal, and a reduction transmission system located in the housing and connected to the rotating shaft and the lamp cover bracket respectively. Since the rotary lamp holder is compact in structure and size and can completely match any standard lamp holder and lamp cover, it can become a universal substitute for the lamp holder mounted on ordinary lamps.