The present invention provides a device and method for interleaved encoding RS code, the RS code used being RS (N, K, S). The method comprises: firstly, writing the data in the data packets to be RS interleaved encoded into the information region of the RS code byte interleaver column-by-column in turn; then, constructing the data of each row of the check region based on the data written into the information region; finally, performing cyclic shifting processing on the data of the check region, and reading out the data of the check region in the RS code byte interleaver column-by-column in turn. The present invention can be used to improve the performance of the entire data packet outputted, thereby enhancing the reliability of the data link layer, by evenly spreading the areas with a filled value of 0 in the last column of the information region that is filled with valid information and by performing cyclic shifting processing on the data of the check region so that the data of that region offer larger time span and good diversity effect when outputted.