Design a open platform for image processing based on.net virtual machine. The virtual machine technology can solve the cross-platform problem and the compatibility problem of memory model. Breaking the traditional platform which is closed to user and difficult development issues. Platform is completely open to the user, set few absolute format specifications. So that all the existing image processing function modules can be most integrated and reuse. Finally through the optimization experiments of threshold image segmentation algorithm verifies the effectiveness of the platform and ease of use.