The invention relates to an optimized demodulation method based on quadrature amplitude in the field of wireless communication. The method comprises the following steps: the absolute values x and y of corresponding x and y in a received QAM signal are obtained, a demodulation soft value is calculated, and a soft value storage list is obtained; after being fragmented compression optimization, the soft value storage list is fragmented and merged, thereby obtaining an optimized demodulation list; line numbers of the optimized demodulation list are sorted in an ascending way according to the fragment indexes; according to the QAM signal received by the demodulation terminal, lines on which the fragment indexes are positioned in the corresponding optimized demodulation list are determined, and corresponding demodulation soft values are obtained by calculation; and finally, decoding symbols are obtained according to the demodulation soft values until the complete demodulated QAM signal is obtained. Corresponding to the size of an original list, the invention is greatly shrunk, addition, subtraction, multiplication, division, shift and other arithmetic do not need to be carried out, and the method can meet the requirement on real time and can ensure that the positive and negative accuracy error does not exceed unit 1.