A method for collective control of lights comprises connecting a positive output and a negative output of a main control device (1) by a wire to form a closed output circuit (4); independently connecting each of a plurality of lights (2) to an auxiliary control device (3); coupling a transducer (31) of each auxiliary control device with the output circuit; encoding each light (2); and inputting a code number of a light to be controlled to the main control device, the main control device generating and outputting an encoded control signal in response to the code number, the encoded control signal passing through the wire of the output circuit, the transducer of an auxiliary control device in association with the light to be controlled generating a control signal in response to the encoded control signal, thereby controlling the lights. A system for collective control of lights is also disclosed.