The invention discloses a coding and decoding method of a transmission control protocol based on network coding. The method optimizes the coding method at a network coding layer, distinguishes normaldata packets or redundant packets, adopts different coding ways for different types of data packets, and realizes the coding for normal coding data packets by adopting a direct exclusive or way; and for redundant data messages, the coding coefficients are randomly selected from a certain row in a Vandermonde matrix, and redundant coding data packets are obtained according to the coding coefficients by using a linear coding method, so that the coding complexity is reduced; in a network layer, the design of the head of the coding data packets is optimized, and the coding coefficients and parameters needed for decoding are considered comprehensively, which shortens the overhead of coding the heads and improves the transmission efficiency; and a decoding algorithm is optimized in the network coding layer, which makes a Gaussian elimination process more simple, thereby reducing the decoding complexity.