Abstract: An experimental scheme for the stability of the laser-welded metal sandwich beam under axial compression loads is designed in this paper. The critical load and failure mode of the sandwich beam are also obtained through the experiment. Meanwhile, the stability of the sandwich beam is analyzed by using the numerical software ANSYS, where the simulation results agree well with the experimental data. Then, the effect of geometric parameters on the critical buckling bearing capacity of the sandwich beam under axial compression loads is studied, and the results show that increasing the thickness of the bottom face sheet as well as the thickness of the core layer is superior in improving the critical buckling bearing capacity of the sandwich beam if the same weight is to be added.