The third generation of artificial neural network-pulse coupled neural network(PCNN) is greatly concerned in the image segmentation field.in the article described the PCNN modular concept.summarized the question which PCNN to have applied in image division when exists.has analyzed the methods and principle which to solve these questions.Based on this.points out the merits and faults of each method.forecast PCNN to apply in the image division research direction.the theoretical needs further study.which can d...