Abstract: The comprehensive drillings against large-scale blackout event, due to its complexity, exhibits such problems as the difficulties in implementation and overall management etc. First, it is a necessity to well prepare emergency drill technical guarantees, including communication support, screen display control and power supply, and then provide guarantee in logistics for the emergency drill, mainly including field preparation, venue layout, reception of drill and observation personnel, drill publicity, etc. Taking an emergency drill of a certain power generation enterprise as an example, this paper introduces the practice in guarantee for its comprehensive drill safeguards against large-scale blackouts.