The present invention discloses a fire extinguishing system for a battery pack, including a detection control apparatus, a fire suppression apparatus, and a hydrant water extinguishing apparatus. The detection control apparatus is disposed inside or outside a battery pack. The fire suppression apparatus and the hydrant water extinguishing apparatus are disposed outside the battery pack. The detection control apparatus is connected to the fire suppression apparatus. The hydrant water extinguishing apparatus is connected to the fire suppression apparatus. Beneficial effects: It is ensured that initial fire can be suppressed and later reignition can be resolved, so that fire extinguishing is adequate. Fire is directly extinguished at a core position inside the battery pack. An exhaust filter device gains valuable time after initial fire extinguishing.