In order to take into account both optical fiber data communication and environment perception in a narrow space, a flexural three-core optical fiber is designed and prepared for the integrated system. The fiber has a triangular core arrangement and a deeply fluorine-doped refractive index channel structure with a standard outer diameter of 125 μm. The transmission characteristics of the O-band (1 260~1 360 nm) are optimized, and the Brillouin gain spectrum（BGS） distribution is similar to that of the G.657.A1 optical fiber. The test results show that the average loss of the core layer is 0.58 dB/km at 1 310 nm wavelength, and the average intercore crosstalk is lower than -50 dB/km. When the minimum bending radius R=10 mm and winding 50 times, the bending loss of the optical fiber is less than 0.1 dB.