A crosstalk estimation method, characterized in: receiving (500, 111), by a transceiver at one end of a first line, a first pilot sequence allocated by a vectoring control entity in a digital subscriber line system; generating and sending, by the transceiver at the one end of the first line, a first pilot training signal and a third pilot training signal according to the first pilot sequence, wherein the first pilot training signal is a pilot training signal of the first line within an overlapping spectral range of the first line and a second line, the third pilot training signal is a pilot training signal of the first line out of the overlapping spectral range of the first line and the second line, and an out-of-band spectrum of the second line overlaps an inband spectrum of the first line; generating, by a transceiver at a peer end of the first line, error sample signals according to the first pilot training signal and the third pilot training signal; and sending (510, 114), by the transceiver at the peer end of the first line, the error sample signals to the vectoring control entity, so that the vectoring control entity determines a first crosstalk channel coefficient from the second line into the first line according to the error sample signals, the first pilot sequence, and a second pilot sequence, wherein the second pilot sequence is a pilot sequence allocated by the vectoring control entity to the second line, the first pilot training signal is orthogonal to a second pilot training signal generated by a transceiver at one end of the second line according to the second pilot sequence, and the third pilot training signal is orthogonal to an out-of-band mirror signal of the second pilot training signal. receiving (500, 111), by a transceiver at one end of a first line, a first pilot sequence allocated by a vectoring control entity in a digital subscriber line system; generating and sending, by the transceiver at the one end of the first line, a first pilot training signal and a third pilot training signal according to the first pilot sequence, wherein the first pilot training signal is a pilot training signal of the first line within an overlapping spectral range of the first line and a second line, the third pilot training signal is a pilot training signal of the first line out of the overlapping spectral range of the first line and the second line, and an out-of-band spectrum of the second line overlaps an inband spectrum of the first line; generating, by a transceiver at a peer end of the first line, error sample signals according to the first pilot training signal and the third pilot training signal; and sending (510, 114), by the transceiver at the peer end of the first line, the error sample signals to the vectoring control entity, so that the vectoring control entity determines a first crosstalk channel coefficient from the second line into the first line according to the error sample signals, the first pilot sequence, and a second pilot sequence, wherein the second pilot sequence is a pilot sequence allocated by the vectoring control entity to the second line, the first pilot training signal is orthogonal to a second pilot training signal generated by a transceiver at one end of the second line according to the second pilot sequence, and the third pilot training signal is orthogonal to an out-of-band mirror signal of the second pilot training signal.