The welding technology and equipment of MIG/MAG and TIG,which are widely applied,have been modified with high efficiency by composite/hybrid welding. It is beneficial to realize high quality and high efficiency welding with low cost,high quality,high depositing rate and high welding speed,and is of great significance to improve the manufacturing efficiency of welding technology. In recent years,MIG/MAG,TIG and other arc welding technologies and equipment with high efficiency have been introduced at home and abroad. In this paper,the principle and application of high efficiency welding technology of double arc pool,such as double wire MIG/MAG welding,double MIG/MAG double-sided welding,double TIG composite welding and TIG-MIG composite welding are summarized. Finally,the new technology of MAG-TIG double arc heat source composite high-efficiency root welding is introduced emphatically.