With the development of social economy, the phenomenon of urban traffic congestion is becoming more and more serious. The widening reconstruction of the existing urban bridges can greatly relieve the pressure of urban traffic. However, due to the specificity of the existing structure and the span layout of new bridge, the structure connection between the old and new bridges cannot be made directly. Therefore, it is necessary to further study the new splicing constructions. The splicing methods of conventional spliced bridges are summarized. And based on the practical projects, aiming at the problems of the insufficient bearing capacity of the cantilever arm of old bridge and the difficulty of reinforcement, a kind of structure used for the bridge widening under the complex working conditions is proposed, which can provide a reference for the design and construction of the similar bridge widening structures.