The invention provides an electricity utilization information self-adaptive mixed carrier wave acquisition system and method; after a broadband carrier wave communication module is electrified, a self mode is defaulted to be a full carrier wave communication mode, the broadband carrier wave communication module is communicated with a user electricity meter by using a default serial port configuration and an electric meter protocol, if communication is successful, the current configuration is saved, and normal work is performed; if communication is unsuccessful, the mode is switched into a semi carrier wave communication mode, the electric meter protocol is used, the serial port configuration is switched and communication continues to try, and if successful, the current configuration is saved. According to the method and system disclosed by the invention, the full carrier wave and semi carrier wave communication acquisition modes can be realized, different carrier wave communication modes are selected according to acquisition devices, and the self-adaptive ability is strong.