The invention relates to a concentrator-based IO expansion auxiliary circuit, which comprises a microprocessor unit, an RS485 communication unit, a power conversion unit, an 8-way remote communicationinterface unit, an 8-way remote control interface unit, a remote communication alarm unit, a Beidou positioning unit, and a clock unit. The problem that the concentrator uses a single interface is thus solved. Use of the concentrator is promoted, the use efficiency is improved, mounting operation is facilitated, a broadband carrier concentrator is promoted to be responsible for managing, readingand storing information of all local meters or collectors, and various types of event data are based on a single communication channel mode.