LED signal light

An LED (light-emitting diode) signal light comprises a light source composed of a plurality of LEDs mounted on a circuit board and light is cast from a front mantle capable of modulating optically, wherein an external lateral surface of the front mantle is a smooth plane while an internal lateral surface is provided with a plurality of lens cells, which are located oppositely against the LEDs correspondingly. Both the architecture of the cutaway and the cross sections of the lens cell implicate an arcuate curve with an opening oriented a smooth plane. Light cast from an LED will undergo optical modulation of the plurality of lens humps on the lens cell so as to redistribute the light in vertical and horizontal direction and adjust orientation of light to the specified illumination areas.