A multiplexing method for data switching is disclosed. In the method, a continuous data is received, and the continuous data includes a plurality of super frames, and each super frame includes a plurality of frames. These super frames are divided into a set of even super frames and a set of odd super frames. The frames included in the set of odd super frames are sorted by corresponding required bit error rate of each frame decreasingly or increasingly. The frames included in the set of even super frames are sorted by the required bit error rate of each frame increasingly or decreasingly. An encoder is used to encode these sorted super frames.