Abstract: In the process of vacuum oxygen decarburization (VOD) refining for stainless steel,the vacuum boiling of molten slag and steel is a kind of intractable and ubiquitous metallurgical problem. The generation,performance,and harm of vacuum boiling were described. Some effective measures to prevent and control the vacuum boiling were introduced. The results show that,the prevention can be realized by stabilizing the initial condition of melts and strengthening the management of ladle state; controlling the process and technical parameters of VOD vacuum refining reasonably is the key to avoid vacuum boiling; in addition,the innovatory design of the VOD vacuum cover can also weaken the harm of vacuum boiling to a certain extent.