Stress and deflection monitoring under asymmetric loading during bridge construction is the core link to ensure structural safety. In this paper, a set of dynamic monitoring and analyzing methods for asymmetric loads is proposed by combining machine vision technology and mechanics theory, and its effectiveness is verified by the engineering case of A bridge. Based on machine vision technology, a four-coordinate system transformation model is established through camera calibration and distortion correction, which eliminates radial and tangential distortion and realizes the accurate restoration of spatial geometric information in the image. In view of the load imbalance between the railroad side and the highway side, the asymmetric cable force mechanics balance equation is established, and the formula for calculating the ratio of the cable force is deduced. Considering the influence of ambient temperature further, a comprehensive calculation method of temperature difference stress in box girder is proposed to quantify the distribution law of temperature difference due to sunshine and cold current and its influence on the longitudinal restraining stress. In the actual engineering verification, by comparing the internal force and stress data of the main pier, such as 50# pier section A bending moment 17075 kN·m and 51# pier-16993 kN·m, the west pier was determined as the force control point, and the top thrust force of 7812 kN was applied. The data analysis shows that the jacking force significantly optimizes the force of the main pier and eliminates the tensile stress of the cross-section, the stress at the upper edge of the A section decreases from 0.83 MPa to -2.12 MPa, and the bending moment adjustment of the main beam reaches 98%, and the reversal of cross-section 1 from – 21243 kN·m to 429 kN·m. In addition, the sensitivity analysis of the friction coefficient of the reserved pipeline shows that when the coefficient fluctuation is ± 10%, the maximum displacement difference in the middle span of the main girder in the bridge state is 0.92 mm, indicating that the construction parameters have a significant influence on the deflection.