The invention discloses an interleaving method. The method comprises: presetting polynomial parameters corresponding to various interleaving depths K and forming a polynomial parameter table; acquiring the length K of coding sequences when Turbo encoding/decoding is performed and determining a permutation sequence used to interleave the coding sequences according to corresponding relation and permutation polynomials in the polynomial parameter table; and interleaving the coding sequences according to the permutation sequence. The performance of a whole Turbo encoding/decoding system can be improved by applying the interleaving method.