The present invention provides a multicolor signal light and a controlling method thereof. The multicolor signal light includes: a multicolor layer, comprising a plurality of lights being capable of lighting multicolor lights and arranged in a certain pattern; a single control signal line for receiving a control signal from a controller outside; a processor for controlling the multicolor layer to light in a different mode and in a different color according to the control signal received by the single control signal line; and power supply terminals for receiving power supply voltage from outside.