Carotid artery intima-media thickness and cardiovascular-cerebrovascular diseases are closely related, is an important index for the prediction of cardiovascular and cerebrovascular diseases. In this regard, the projection section based Otsu method was introduced to the carotid artery intima-media segmentation, and a high quality of the carotid artery intima-media segmentation methods are proposed. In this method, the Otsu method is extended to multi threshold in order to deal with the multi-objective of the image of the carotid artery. Then, the particle swarm algorithm is used to search the optimal threshold to improve the efficiency of the algorithm. Clinical data test results show that the method has obvious advantages in anti noise and aging, and it can provide important reference for prevention, diagnosis, treatment and computer aided diagnosis of cardiovascular diseases.