A brief introduction has been made to the features and hazards of the welding fume, followed by an analysis of recent studies on the ventilation purification of the welding fume. Methods concerning echanical ventilation purification mainly include local dust precipitation, total ventilation and displacement ventilation, with the last one being a new kind of dilution ventilation suitble for spacious welding workshops. Therefore an emphatic analysis has been made of the application of displacement ventilation to welding fume control in confined spaces. Finally a summary and investigation has been made of the existing problems and future development of welding fume ventilation purification.