A thin indication and warning device includes one or more self-powered indicator units 1 adapted to assemble together by means of a connector 2. The indicator unit 1 includes a channel member 11 including a recessed base 111 and a cover 112 including openings 115; light indicators 12 each including a housing 121 aligned with the opening 115, and a light-emitting member 122 mounted under the housing 121; a control circuit 14; and a rechargeable power supply 13. In response to power outage an abnormal voltage detection circuit 126 detects same and sends an activation signal to the power supply 13, the enabled power supply 13 supplies power to an alarm circuit 143 and each light indicator 12 respectively, the enabled alarm circuit 143 makes a warning sound, and each light indicator 12 emits light for indication.