Tailor-welded blanks (TWBs) have been widely applied in the automotive industry owing to better balance between light weight and crashworthiness. The obvious feature of the TWBs is the existence of weld lines. This paper numerically compares the modelling strategies of the weld line under quasi-static and dynamic events. A novel method with crossover scheme is proposed. For the quasi-static tests, those existing modelling methods such as rigid links (RL), onefold beam (OB)/twofold beam (TB), shell (SH)/solid model (SN) and new crossover model are compared. Note that the SH/SN model is considered to be accurate and as the baseline model. Through the deformation analysis and equivalent plastic strains under the static scenario, it indicates that the novel scheme is superior to other modelling methods. Then, the method is further applied to dynamic impacting. Those results provide important information for numerical modelling especially when TWBs are fabricated through different materials with a relatively higher thickness ratio.