The invention provides a device for realizing remote automatic meter reading (live wire meter reading in short) by use of a resident power supply network. The remote means 500m in diameter. Two remote meter reading schemes are mainly reported at present: one is infrared transmission, and the other is optical fiber network transmission; and two mentioned schemes are described in the text. The meter reading device (the device structure and components are as shown in abstract figure) is networked through a computer so that the user instrument data can be conveniently sent to a set of far-end central control equipment. Various component function characteristics of the device are described in the text, and the condition that an ultra-low carrier frequency selection is a key parameter for realizing low cost and high reliability in the live wire meter reading technology is proofed, and some difficult points needing to be solved in the circuit are explained. In the end, the text forecasts the prospect of the product. For convenience, a main station device in the following description is called as a main station for short, and the user station device is called as a user station for short.