Abstract. Partial differential equation(PDE) plays an important role in the field of image segmentation in biological detection. According to the analysis of some problems existing in the process of current biological detection image segmentation, this research set up a kind of image analysis and processing of biological detection algorithm based on PDE.Through the analysis of PDE in image processing and application situation of development methods, this study constructed a biological detection image segmentation application model based on PDE. The results show that the PDE is a mathematical operation as the foundation, and with an open framework for development mode. PDE is a biological detection very effective image segmentation analysis tool that can solve the image topology in biology of high complexity and noise problems.