Abstract: The present disclosure provides an audio quantization coding and decoding device and a method thereof. In the method, before a quantization coding process is performed on a digital signal, the signal is pre-processed, the digital signal is split into multiple frames based on positive and negative half periods of the signal, and all audio data between two adjacent zero-crossing points belongs to the same positive and negative half periods, so as to have the same sign-bit. A pre-processing module groups the numeric data belonging to the same positive and negative half periods into the same frame. When coding, an audio quantization coding module only needs to record a sign-bit of the frame at a head of the frame, so the sign-bit of each batch of voice data in the frame may be omitted to reduce a data amount or improve a resolution of each batch of voice data.