An embodiment of the present disclosure contemplates a data sending and receiving method and apparatus. A first FEC unit of a sending device sends, by using a first channel, a first data stream on which first FEC encoding has been performed; a second FEC unit of the sending device sends, by using a second channel, a second data stream on which second FEC encoding has been performed; and the sending device performs interleaving on the first data stream and the second data stream, to obtain an output data stream, and sends the output data stream to a receiving device.