A processing method for channel changing in a joint transceiving mode, characterized by comprising: performing fault detection for one or more direct channels in transmission channels for joint transceiving between one central office end and multiple terminals, wherein the transmission channels are on a group of lines on which joint transceiving has already been implemented; after a fault is detected on a direct channel of the transmission channels for joint transceiving, stopping sending signals on the direct channel with fault; detecting whether the direct channel with fault has been recovered; and when recovery of the direct channel with fault is detected, resuming sending signals on the direct channel; wherein the performing the fault detection for one or more direct channels comprises: determining whether the fault occurs on the direct channel by detecting a change of total energy of signals transmitted on the direct channel, which further comprises: getting squares of discrete values on a frequency domain, and adding the squared sampling values to obtain a detection value; comparing the detection value with a standard value; and if a ratio of the detection value to the standard value is smaller than a preset threshold value, determining that the fault occurs on the direct channel. performing fault detection for one or more direct channels in transmission channels for joint transceiving between one central office end and multiple terminals, wherein the transmission channels are on a group of lines on which joint transceiving has already been implemented; after a fault is detected on a direct channel of the transmission channels for joint transceiving, stopping sending signals on the direct channel with fault; detecting whether the direct channel with fault has been recovered; and when recovery of the direct channel with fault is detected, resuming sending signals on the direct channel; wherein the performing the fault detection for one or more direct channels comprises: determining whether the fault occurs on the direct channel by detecting a change of total energy of signals transmitted on the direct channel, which further comprises: getting squares of discrete values on a frequency domain, and adding the squared sampling values to obtain a detection value; comparing the detection value with a standard value; and if a ratio of the detection value to the standard value is smaller than a preset threshold value, determining that the fault occurs on the direct channel. determining whether the fault occurs on the direct channel by detecting a change of total energy of signals transmitted on the direct channel, which further comprises: getting squares of discrete values on a frequency domain, and adding the squared sampling values to obtain a detection value; comparing the detection value with a standard value; and if a ratio of the detection value to the standard value is smaller than a preset threshold value, determining that the fault occurs on the direct channel. getting squares of discrete values on a frequency domain, and adding the squared sampling values to obtain a detection value; comparing the detection value with a standard value; and if a ratio of the detection value to the standard value is smaller than a preset threshold value, determining that the fault occurs on the direct channel.