The paper aims to study stress and deformation of bracket during calibration of the weighing sensor. The finite element analysis technique was adopted to simulate the calibration process of the symmetric weight sensor. The stress and deformation of the bracket during calibration of the weighing sensor were studied, and the finite element analysis results of the bracket were verified. Through analysis on the simulation results, the stress concentration part of the bracket of the load cell calibration device was found. The optimized design is used to round the stress concentration part of the bracket. As a result, the strength and rigidity of the bracket are greatly improved.