The arc cavern behavior and its influence of submerged arc welding were reviewed. The results show that the arc cavern is a three-dimensional arc space with a top round and the bottom molten pool, consisting of a semi molten flux wall,and Internally filled with metal vapor and flux decomposition mixture. The arc shape in the cavern should belong to the continuous and inactive type,and the flux-wall guided transfer is the dominant transfer form in single wire submerged arc welding. The phenomenon of oxygen gaining occurs in the droplet and weld metal inside the arc cavern,and the content of oxygen gaining in the droplet is maximum,the polarity of the power supply and current changes affect the oxygen gaining content. The reaction of silicon reduction and oxygen gaining in the droplet reaction zone proves the fact of oxygen gaining in the cavern. The polarity of the power supply and the flux slag basicity may make the droplet oxygenation and fining droplet,but does not change the flux-wall guided transfer form of the droplet.