In order to select fibers which are sensitive to macrobending loss,optical devices based on optical fiber macrobending loss are developed,and the main factors affecting macrobending loss of single mode fibers are analyzed theoretically and simulated.Simulation study is carried out to investigate the impact of coating layers,bend radius,light wavelength,MAC value and the number of bend turns on the macrobending loss of optical fiber,based on two theoretical models of a bend fiber with a core-infinite cladding structure and a bend fiber with a core-cladding-infinite coating layer structure,which are developed by D.Marcuse and H.Renner,respectively.The three types of fibers chosen for the simulation research are Corning SMF28,Corning SMF28e and Nufern 1060XP single mode fiber.Results show:(i)The macrobending loss of a single mode fiber with a core-infinite cladding structure increases with increase of wavelength,decrease of bend radius,increase of bend turns and increase of MAC value;(ⅱ)Oscillation phenomena of macrobending loss for a fiber are induced by the coating layers such as acrylate;(ⅲ)MAC is one parameter to affect the inherent macrobending loss performance of a fiber,while MAC value is the key parameter to reflect the inherent macrobending loss performance,as well as an important parameter to select a fiber that is sensitive to bend loss.Therefore,optical devices based optical fiber macrobending loss are suitable to choose single mode fibers with large MAC value,long wavelength,small bend radius,more bend turns,and especially a core-infinite cladding structure,which is realized by removing the coating layers and adding an absorption layer.