Image binary segmentation is the most fundamental and important preprocessing in image analysis and pattern recognition, which directly affects analyses and results of post-processing. The crucial step in image data processing of automatic locust detection system (ALDS) is image segmentation. A parametrically simplified pulse-coupled neural network (PCNN) was brought forward. Experiments were done on locust images. Area recognition rate (ARR) achieved 94%. The results of computer simulation showed that the objects (locusts) in the image were easier to be found by using PCNN than by the‘open’operation. The performance of PCNN in image processing has been tested, and a new approach to detect locusts has been developed.