The present invention relates to the field of single-mode optical fibers and discloses a bending-insensitive, radiation-resistant single-mode optical fiber, sequentially including from inside to outside: a core, inner claddings, and an outer cladding, all made from a quartz material. The inner claddings comprise, from inside to outside, a first fluorine-doped inner cladding and a second fluorine-doped inner cladding. The core and the first fluorine-doped inner cladding are not doped with germanium. The respective concentrations of other metal impurities and phosphorus are less than 0.1 ppm. By mass percent, the core has a fluorine dopant content of 0-0.45% and a chlorine content of 0.01-0.10%; the first fluorine-doped inner cladding has a fluorine concentration of 1.00-1.55%; and the second fluorine-doped inner cladding has a fluorine concentration of 3.03-5.00%.