本文介绍利用自行研制的模拟不同水深的加压仓焊接试验装置,在气体压力P_g=0～7公斤/厘米~2(相当于水深70米以浅)的高压CO_2气体中,对焊接电弧特性、工艺特性以及冶金特性进行的系统研究结果。提出了一种在高压CO_2气体中焊接电弧的新型控制法。研制的双阶梯复合外特性电源是实现焊接电弧新型控制法的重要手段。 This paper introduces the welding arc welding equipment which simulates the different depths of the pressurized chamber by self-developed test equipment. The characteristics of the welding arc, the process of the arc welding, the high pressure CO_2 gas with the gas pressure of P_g = 0 ~ 7kg / cm_2 (corresponding to the water depth of 70m) Characteristics and metallurgical properties of the system research results. A new control method of welding arc in high pressure CO_2 gas is proposed. Developed double ladder composite external power source is to achieve a new method of welding arc control an important means.