Focal cortical dysplasia (FCD) is one of the causes of drug refractory epilepsy. In clinical treatment, surgical excision is often used to remove the FCD lesion area. Therefore, it is very important to detect and locate the lesion area before operation. The Study showed an increase in the cortical thickness of FCD, and it is hypometabolic in the lesions with a lower value in PET images. In this work, this paper uses a voxel based Laplace method to calculate the cortical thickness, and combine the thickness image calculated with PET image to get a thickness-PET map in which the lesion area can be visualized more easily. It also developed a graphic user interface (GUI) to help doctors processing and displaying easier.