Abstract: A new friction welding system was developed to join the bulk metallic glass.The Zr₄₁ Ti₁₄ Cu_12.5 Ni₁₀ Be_22.5 bulk metallic glass bars were joined by this welding system.The welded sample was tested by scanning electron microscope,X-ray diffraction,Vickers hardness and transmission electron microscope.The results show that no incomplete fusion or obvious defects are found,and the welded joint maintains the amorphous structure.The hardness is enhanced because a few nanocrystallines occur in the joint.Subsequently,the friction welding temperature field was simulated using finite element software ANSYS.The simulation results indicate that the friction time can not exceed 0.25 s and the upset forging should be carried out.The temperature on center interface exceeds the glass transition temperature of Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5,and the superplastic deformation occurs.It is concluded that the new friction welding system can be used to join the bulk metallic glass bars.The simulation results of temperature field accords well with that of the experiment,which is beneficial to optimize the welding parameters and guide the experiment.