A line digital signal processing device and method. The device includes at least two line accessors and a data processor, where the at least two line accessors are connected to the data processor and each line accessor is not provided with line digital signal processing, and the data processor simultaneously performs line digital signal processing and service data recovery on service data sent by the at least two line accessors, thereby reducing complexity of an access device, and monitoring, maintenance, and alarming are simultaneously performed on complex line digital signal processing components.