Abstract: The micromorphology of CuCoBeZr electrode after 600 spot welding of aluminum zinc plated plate was observed and compared with that of CuCoBeZr electrode without cryogenic treatment, and the effect of cryogenic treatment time on the alloying of CuCoBeZr electrode was discussed.The results show that the CuCoBeZr electrode after cryogenic treatment at -196 ℃has a large amount of Cu on its end face after spot welding 600 points, which can still ensure good conductivity and heat conduction.The comparison of cryogenic effect shows that there is no obvious alloy layer after the CuCoBeZr electrode insulated for 6 h, and the alloying phenomenon disappears at less than 20 μm away from the end surface, and there are fewer holes and cracks at the electrode end, which is the best holding time.