The dynamic action of moving vehicles is an important factor that adversely affects the performance of concrete stitch of the widening bridges. Considering the characteristics of dynamic interaction between cars and bridges, it is necessary to carry out research on reasonable control measures to widen bridges. Firstly, the influence mechanism of vibration caused by traffic load on widening bridge splice joints was analyzed. According to related experimental research results, the control indexes of vertical relative deformation and vibration speed were proposed. For standard span concrete bridges, based on the statistical results of large sample data of vehicle-bridge coupling vibration analysis, a comprehensive control measure design method combining traffic control and piecewise pouring construction was proposed. The analysis of engineering examples shows that the method has good engineering applicability and control effect.