With the development of artificial intelligence, internet of things and communication technology, the form of power grid is changing towards intelligence and information generalization. In order to better meet the needs of ubiquitous power internet of things construction and client-side real-time interactive business, HPLC communication technology comes into being. By analyzing the characteristics of HPLC and the typical application of client-side power grid, this paper provides the methods of low voltage user voltage real-time monitoring, power outage event classification active report and meter error connection identification. The hardware circuit of HPLC has improved. And the communication protocol has expanded. It realizes the deepening application of intelligent meter reading technology based on HPLC. Further, the test cases in typical residential areas such as high-rise apartment and urban-rural fringe are discussed and analyzed. The effectiveness and advancement of the methods are verified. It provides a wide range of business support for marketing, scheduling, operation and maintenance of power system. This work is supported by Science and Technology Project of the Headquarter of State Grid Corporation of China (No. 5400-201925177A) “Research on the Key Technologies of Situational Awareness and Intelligent Warning of Electric Larceny on the Customer Side”.