The embodiment of the invention provides a compression method and system for an audio signal of a pig and belongs to the technical field of compression and transmission of audio signals. The compression method comprises the following steps of acquiring the audio signal; converting the audio signal into a digital signal mode; weighting the audio signal; normalizing the weighted audio signal; windowing and framing the normalized audio signal; carrying out endpoint detection on the windowed and framed audio signal to determining a valid signal part of the audio signal; extracting the valid signalpart to serve as a preprocessed audio signal; and compressing the preprocessed audio signal by spectrum subtraction. Through the adoption of the compression and transmission method and system, the technical problems of information collision and congestion during transmission of the audio signal of the pig in the prior art can be solved.