Sutong Bridge is a cable-stayed bridge with a main span of 1088 m. 370 high-precision stress monitoring measured date shows that in the process of hoisting the steel box girders, the stress of the main girders is in the fluctuant and complex state and many meteorological factors, such as sunshine radiation, temperature and wind, have important implication on the variable stress of the steel box girders. According to the real-time weather date, the stress date after the process of wavelet denoising from representative measuring points in different weather conditions is picked to establish the stress response brought by meteorological factors with Layered Separation method, thereby basically eliminating the influence of meteorological factors on the stress of main girders, so that accurate and reliable stress date can be got for steel box girders adjusting and cable-tensioned construction control.