The product codes using linear block codes set up a mirror in the realization of long codes and hold the outstanding performance for random error and burst correction. It can gain very excellent error-correcting capability when a product code performs decoding with the method of turbo codes based on iterative decodes. The paper describes a new iterative decoding algorithm for the product codes, its feedback method is completed by a linear combination of soft output of encoder and the receipt information is different with the traditional turbo iterative decode. When decoder obtains the soft output matrix built -1 and +1, the complexity can be reduced greatly and the performance can be lost little by reducing the number of candidate code words and omitting the complicated operation of LLR.