The present disclosure provides a method for regulating an inert gas flow in a crystal pulling furnace, a method for preparing monocrystalline silicon, and monocrystalline silicon. The method for regulating an inert gas flow includes introducing the inert gas into a main furnace chamber of the crystal pulling furnace from an auxiliary furnace chamber of the crystal pulling furnace, and regulating a flow direction of the inert gas flow introduced into the auxiliary furnace chamber of the crystal pulling furnace.