An adaptor for electrically connecting a power supply module with a light-emitting module, comprising: a main body, comprising: an outer wall, forming an inner chamber, a power supply mounting part, located at the outer wall and configured to be engaged with the power supply module; a light source mounting part, located at the outer wall and disposed opposite to the power supply mounting part, and configured to be engaged with the light-emitting module; a conducting circuit, located in the inner chamber and configured to be capable of turned on/off, and configured to transmit electric power outputted by the power supply module to the light-emitting module, when the power supply mounting part is engaged with the power supply module and the light source mounting part is engaged with the light-emitting module, and a push-out part, movably connected to the main body, wherein the push-out part is operatively movable to a blocking position and a releasing position; when in the blocking position, the push-out part blocks the power supply mounting part from being engaged with the power supply module, and when in the releasing position, the push-out part releases the power supply mounting part to be engaged with the power supply module, characterized by an operating component, movably connected to the main body and the push-out part, wherein the operating component is operatively movable on the main body to an on-position and an off-position; when the power supply mounting part is engaged with the power supply module, by a resisting force from the power supply module, the push-out part moves to the releasing position and maintains in the releasing position, and the operating component moves to the on-position to turn on the conducting circuit; when the power supply mounting part is separated from the power supply module, the push-out part moves to the blocking position from the releasing position and meanwhile driving the operating component to move from the on-position to the off-position to turn off the conducting circuit, wherein the main body has a longitudinal lengthwise direction along which the operating component is operatively movable on the main body, and the push-out part extends along the longitudinal lengthwise direction of the main body and is_movable along this direction. a main body, comprising: an outer wall, forming an inner chamber, a power supply mounting part, located at the outer wall and configured to be engaged with the power supply module; a light source mounting part, located at the outer wall and disposed opposite to the power supply mounting part, and configured to be engaged with the light-emitting module; a conducting circuit, located in the inner chamber and configured to be capable of turned on/off, and configured to transmit electric power outputted by the power supply module to the light-emitting module, when the power supply mounting part is engaged with the power supply module and the light source mounting part is engaged with the light-emitting module, and an outer wall, forming an inner chamber, a power supply mounting part, located at the outer wall and configured to be engaged with the power supply module; a light source mounting part, located at the outer wall and disposed opposite to the power supply mounting part, and configured to be engaged with the light-emitting module; a conducting circuit, located in the inner chamber and configured to be capable of turned on/off, and configured to transmit electric power outputted by the power supply module to the light-emitting module, when the power supply mounting part is engaged with the power supply module and the light source mounting part is engaged with the light-emitting module, and a push-out part, movably connected to the main body, wherein the push-out part is operatively movable to a blocking position and a releasing position; when in the blocking position, the push-out part blocks the power supply mounting part from being engaged with the power supply module, and when in the releasing position, the push-out part releases the power supply mounting part to be engaged with the power supply module, characterized by an operating component, movably connected to the main body and the push-out part, wherein the operating component is operatively movable on the main body to an on-position and an off-position; when the power supply mounting part is engaged with the power supply module, by a resisting force from the power supply module, the push-out part moves to the releasing position and maintains in the releasing position, and the operating component moves to the on-position to turn on the conducting circuit; when the power supply mounting part is separated from the power supply module, the push-out part moves to the blocking position from the releasing position and meanwhile driving the operating component to move from the on-position to the off-position to turn off the conducting circuit, wherein the main body has a longitudinal lengthwise direction along which the operating component is operatively movable on the main body, and the push-out part extends along the longitudinal lengthwise direction of the main body and is_movable along this direction.