Abstract: In this paper,the vision technology with adaptive control technology are used in TIG welding quality control of the aluminium alloy.The specialties of the TIG welding process for aluminium alloy are analysed,introduced stochastic system theory into the welding process.Then,stochastic models between welding condition and the parameters of weld pool have been established and the on-line identification of the model parameters is realized.The adaptive welding current adjuster based on the minimum variance theory is designed.The experiments show that adaptive system is excellent in controlling weld bead for aluminium alloy TIG welding.