Four different nonlinear weldlines were arranged on the box with laser tailor welded blanks (LTWBs) with different thicknesses, and the formability of box with LTWBs based on different arrangements of non-linear weld line was studied by means of dynamic explicit finite element method. The simulated results demonstrate that different arrangements of non-linear weld line have important effect on the weld line movement of LTWBs box and deformation of connecting region of the weld line. The weld line movement on the flange of the box is validated by experiment. The simulated results are in good agreement with the experimental results. 