As an imaging technique, optical coherence tomography (OCT) is widely adopted in the field of biomedicine. The clear structure of retina can be obtained by OCT, which is important for the diagnosis of retinopathy. In this paper, reviewed are some excellent methods to retina OCT B-scan image segmentation. The OCT segmentation approaches are classified into two distinct groups according to the output-style of segmentation algorithm, which are layer-edge method and layer-self method. The differences among methods are analyzed to provide references to retinal diagnosis and algorithm researches.