The invention discloses an image recognition method based on a three-way decision and a CNN. The method comprises the following steps of inputting a sample data set image to train a CNN classifier; introducing three decision-making ideas in an image segmentation stage, and obtaining three decision-making classifiers by utilizing a positive data set image and a negative data set image which are obtained by classification of a CNN classifier; dividing the image into a positive region, a negative region and a delay decision region by using three decision classifiers; performing iterative classification processing on the delay decision area divided by the classifier; judging whether the remaining delay decision area reaches a critical value or not; when the delay decision area reaches a critical value, indicating that the to-be-identified image cannot be segmented again, and then performing CNN image identification on all positive areas. According to the present invention, the CNN image recognition technology and the three decision theories are combined, the useful information in the image can be fully utilized, and the higher recognition rate is achieved.