Brillouin optical frequency domain analysis (BOFDA) is a kind of distributed fiber sensing technology. In this paper, the development history of BOFDA is reviewed, and the latest application progress of BOFDA is introduced. A new method of measuring bridge deflection based on BOFDA is proposed as well. Firstly, through the study of optical fiber layout, it is proposed that the optical fiber is laid on the bottom of the bridge in a comprehensive pasting way. Then the theory of optical fiber strain characterizing the bridge deflection is analyzed. Finally, the experimental study of indoor bridge model measurement based on BOFDA is carried out. The experimental results show that the deflection of the bridge model measured by the dial indicator is in direct proportion to the graded concentrated load on the bridge model and the fiber strain on the lower surface of the model. The deformation range of the bridge model can be calibrated by BOFDA fiber strain, and the deflection of the bridge model characterized by fiber strain is basically consistent with the deflection measured by the dial indicator. Therefore, it is feasible to use BOFDA technology for bridge deflection measurement.