CO_2短路过渡焊接是一种高效、节能的焊接方法,但其飞溅大、熔深浅的问题一直未能根本解决.本文在研究CO_2短路过渡焊接电弧熔滴过渡机理和飞溅产生原因的基础上,提出并实现用于检测液桥收缩程度的电阻变化率检测法,在此基础上实现熔滴短路过渡模式下焊接电弧的闭环控制,有效地抑制了短路过渡中的焊接飞溅,取得较好的工艺效果. CO_2 short-circuit transition welding is an efficient and energy-saving welding method, but the problem of large spatter and shallow welding depth has not been solved completely.Based on the research of transition mechanism and spatter of CO_2 short-circuit transition welding arc, And the method of detecting the rate of change of the resistance for detecting the liquid bridge shrinkage is realized. On the basis of this, the closed-loop control of the welding arc in the droplet short-circuit transition mode is realized, the welding spatter in the short-circuit transition is effectively suppressed, and a better process effect is achieved .