A noise signal processing apparatus, comprising a digital front end, DFE, a transmitter circuit, and a first receiver circuit, wherein the transmitter circuit is configured to: receive a signal from the DFE, process and amplify the signal, and output the signal, the output signal comprises a first noise signal, and the first noise signal flows into the first receiver circuit, and the noise signal processing apparatus further comprises a second receiver circuit, a filter module, an adder module, and a delay module, wherein the first receiver circuit is connected to the DFE by using the delay module and the adder module, and the first noise signal is processed by the first receiver circuit and the delay module to obtain a second noise signal; the second receiver circuit is connected to an output end of the transmitter circuit, and is configured to: receive the first noise signal output by the transmitter circuit, and send the first noise signal to the filter module; the filter module is connected to the DFE and the second receiver circuit, and is configured to: receive a filter coefficient sent by the DFE, and perform, by using the filter coefficient, filtering processing on the first noise signal received by the second receiver circuit, to obtain a third noise signal; and the adder module is connected to both the delay module and the filter module, and is configured to: add the received second noise signal and the received third noise signal to obtain a first signal, and send the first signal to the DFE; wherein the transmitter circuit comprises a digital-to-analog converter, DAC, a programmable gain amplifier, PGA, and a line driver, LD, and the first noise signal is generated after a digital subscriber line, DSL, signal output from the DFE sequentially passes through the PGA and the LD, and the apparatus further comprises a first high-pass filter, HPF 1, a second high-pass filter, HPF 2, and a hybrid circuit, H; the hybrid circuit H is disposed between the LD and the HPF 1, and is configured to send, to the HPF 1, the first noise signal output by the LD; an input end of the HPF 1 is connected to the hybrid circuit H, and an output end is connected to the first receiver circuit; and an input end of the HPF 2 is connected to the LD, and an output end is connected to the second receiver circuit; and wherein the apparatus further comprises a transformer, TF, and a switching module, and one end of the TF is connected to the hybrid circuit, H; and the switching module is connected between the HPF 2 and the second receiver circuit, and is configured to perform switching to collect the first noise signal output by the LD or a common mode noise collected by the TF on a twisted pair. the noise signal processing apparatus further comprises a second receiver circuit, a filter module, an adder module, and a delay module, wherein the first receiver circuit is connected to the DFE by using the delay module and the adder module, and the first noise signal is processed by the first receiver circuit and the delay module to obtain a second noise signal; the second receiver circuit is connected to an output end of the transmitter circuit, and is configured to: receive the first noise signal output by the transmitter circuit, and send the first noise signal to the filter module; the filter module is connected to the DFE and the second receiver circuit, and is configured to: receive a filter coefficient sent by the DFE, and perform, by using the filter coefficient, filtering processing on the first noise signal received by the second receiver circuit, to obtain a third noise signal; and the adder module is connected to both the delay module and the filter module, and is configured to: add the received second noise signal and the received third noise signal to obtain a first signal, and send the first signal to the DFE; wherein the transmitter circuit comprises a digital-to-analog converter, DAC, a programmable gain amplifier, PGA, and a line driver, LD, and the first noise signal is generated after a digital subscriber line, DSL, signal output from the DFE sequentially passes through the PGA and the LD, and the apparatus further comprises a first high-pass filter, HPF 1, a second high-pass filter, HPF 2, and a hybrid circuit, H; the hybrid circuit H is disposed between the LD and the HPF 1, and is configured to send, to the HPF 1, the first noise signal output by the LD; an input end of the HPF 1 is connected to the hybrid circuit H, and an output end is connected to the first receiver circuit; and an input end of the HPF 2 is connected to the LD, and an output end is connected to the second receiver circuit; and wherein the apparatus further comprises a transformer, TF, and a switching module, and one end of the TF is connected to the hybrid circuit, H; and the switching module is connected between the HPF 2 and the second receiver circuit, and is configured to perform switching to collect the first noise signal output by the LD or a common mode noise collected by the TF on a twisted pair.