Abstract: By means of chemical composition analysis, tensile property test, microstructure analysis and so on, the cracking causes of 2A14 aluminium alloy container were analyzed. The results show that the main reason for cracking of the 2A14 aluminium alloy container was the hydrogen holes near the fusion line of the welding joints. The welding hydrogen holes reduced the compactness and effective bearing area of the welding joints. The capacity of deformation resistance of the joints was weakened, and eventually it resulted in the cracking and failure of the container.