According to different classification methods, fiber optic connectors can be divided into different categories, which can be divided into single-mode fiber optic connectors and multi-mode fiber optic connectors according to different transmission media. According to different structures, it can be divided into FC, SC, ST, D4, DIN, Biconic, MU, LC, MT and other types. According to the connector pin end face can be divided into FC, PC (UPC) and APC; According to the number of fiber core points and single core, multi - core points.