In the field of flow metering, there is relatively little research on vortex flow measurement using fiber optic sensing technology, so it has important research significance. The paper designed a cantilever beam type fiber Bragg grating vortex flow sensor is designed, which utilizes the vibration of the free end of the cantilever beam to periodically shift the center wavelength of the fiber Bragg grating, thereby measure the vortex frequency and get the fluid flow information. The temperature sensing test and flow sensing test are carried out. The results show that the temperature sensitivity of the sensor is 17 pm/℃, the vortex flow sensitivity is 0.018 95 Hz/（L·h-1）, and the nonlinear error is 2.23%, which verifies that the sensor can be applied to measure the liquid vortex flow.