An embodiment of the present invention discloses a data sending and receiving method. 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 and error correction capability of a receiving device could be improved. In addition, in the present invention, an operation of writing by row and reading by column does not need to be performed. Therefore, no delay is generated.