Abstract: During the construction of a pumping station, the deformation monitoring of the steel template for its suction boxes is of great importance to guaranteeing the safe operation of pumps. Pulse-prepump Brillouin optical time domain analysis (PPP-BOTDA) method is applied for the pump deformation monitoring to overcome the shortcomings of traditional methods with regard to poor adaptability to complicated shaped surfaces and the constraints of environmental factors. A temperature compensation method is proposed to solve the problem that the Brillouin frequency shift is sensitive to both temperature and strain. An improved conjugated beam method is then adopted to convert the strain after removing the temperature effect to structural deformation. The method is successfully applied to the deformation monitoring of steel templates for suction boxes of a drainage pumping station. The results show that tensile strain and deformation occurred on the top and both sides of the steel templates, and increased during concrete pouring and stabilized after completion. The feasibility and superiority of the proposed method is validated, which provides an important reference for the research and application of structural deformation monitoring.