A direction light and illumination device for bicycle includes a direction light unit arranged to a bicycle handling and a rear portion of a bicycle frame. The direction light unit includes a front support, a rear support, a front left light, a front right light, a rear left light, a rear right light, and a controller. The front left light and the front right light are arranged to two ends of the front support. The rear left light and the rear right light are arranged to two ends of the rear support. The controller is electrically connected to all direction lights so as to light up both two right or left lights for indicating a turning direction for safety.