An electric appliance identification method, comprising: obtaining, by a power line communication, PLC, device, a noise signal in a circuit; obtaining, by the PLC device, first data based on the noise signal, wherein the first data is used to describe a time-frequency feature of the noise signal; and obtaining, by the PLC device based on an electric appliance identification model and the first data, an electric appliance identification result corresponding to the noise signal, wherein the electric appliance identification model is obtained based on a signal comprising a noise signal of at least one known electric appliance, wherein the obtaining, by the PLC device, first data based on the noise signal comprises: dividing, by the PLC device, the noise signal into segments, and obtaining the first data based on the segmented noise signal, wherein a signal length of the noise signal is at least one alternating current cycle, the noise signal comprises N sampling points, and N is a positive integer; and the dividing, by the PLC device, the noise signal into segments, and obtaining the first data based on the segmented noise signal comprises: dividing, by the PLC device, the N sampling points into M segments, and extracting a time-domain feature for each of the M segments to obtain one piece of M-dimensional data, wherein M is a positive integer, and M ≤ N; dividing, by the PLC device, the N sampling points into K segments, selecting L segments from the K segments, and extracting a frequency-domain feature for each of the L segments to obtain L pieces of M-dimensional data, wherein both L and K are positive integers, and L ≤ K ≤ N; and using, by the PLC device, the piece of M-dimensional data and the L pieces of M-dimensional data as the first data. obtaining, by a power line communication, PLC, device, a noise signal in a circuit; obtaining, by the PLC device, first data based on the noise signal, wherein the first data is used to describe a time-frequency feature of the noise signal; and obtaining, by the PLC device based on an electric appliance identification model and the first data, an electric appliance identification result corresponding to the noise signal, wherein the electric appliance identification model is obtained based on a signal comprising a noise signal of at least one known electric appliance, wherein the obtaining, by the PLC device, first data based on the noise signal comprises: dividing, by the PLC device, the noise signal into segments, and obtaining the first data based on the segmented noise signal, wherein a signal length of the noise signal is at least one alternating current cycle, the noise signal comprises N sampling points, and N is a positive integer; and the dividing, by the PLC device, the noise signal into segments, and obtaining the first data based on the segmented noise signal comprises: dividing, by the PLC device, the N sampling points into M segments, and extracting a time-domain feature for each of the M segments to obtain one piece of M-dimensional data, wherein M is a positive integer, and M ≤ N; dividing, by the PLC device, the N sampling points into K segments, selecting L segments from the K segments, and extracting a frequency-domain feature for each of the L segments to obtain L pieces of M-dimensional data, wherein both L and K are positive integers, and L ≤ K ≤ N; and using, by the PLC device, the piece of M-dimensional data and the L pieces of M-dimensional data as the first data. dividing, by the PLC device, the noise signal into segments, and obtaining the first data based on the segmented noise signal, wherein a signal length of the noise signal is at least one alternating current cycle, the noise signal comprises N sampling points, and N is a positive integer; and the dividing, by the PLC device, the noise signal into segments, and obtaining the first data based on the segmented noise signal comprises: dividing, by the PLC device, the N sampling points into M segments, and extracting a time-domain feature for each of the M segments to obtain one piece of M-dimensional data, wherein M is a positive integer, and M ≤ N; dividing, by the PLC device, the N sampling points into K segments, selecting L segments from the K segments, and extracting a frequency-domain feature for each of the L segments to obtain L pieces of M-dimensional data, wherein both L and K are positive integers, and L ≤ K ≤ N; and using, by the PLC device, the piece of M-dimensional data and the L pieces of M-dimensional data as the first data. dividing, by the PLC device, the N sampling points into M segments, and extracting a time-domain feature for each of the M segments to obtain one piece of M-dimensional data, wherein M is a positive integer, and M ≤ N; dividing, by the PLC device, the N sampling points into K segments, selecting L segments from the K segments, and extracting a frequency-domain feature for each of the L segments to obtain L pieces of M-dimensional data, wherein both L and K are positive integers, and L ≤ K ≤ N; and using, by the PLC device, the piece of M-dimensional data and the L pieces of M-dimensional data as the first data.