The invention discloses a method for efficiently removing CO2 from flue gas with utilization of a hollow fiber hydrophobic membrane. The method comprises the following steps of: removing dust from the flue gas of an afterheat furnace and then cooling the flue gas in a flue gas heat exchanger; putting the flue gas in a hollow fiber membrane contactor I to chemically react with an absorption liquid, and directly exhausting the flue gas to the air after removing the CO2; sending the absorption liquid to the flue gas heat exchanger to cool after reaction, and desorb a part of the CO2 from the absorption liquid, then sending the absorption liquid to a hollow fiber membrane contactor II, heating and separating the CO2; returning the absorption liquid from which the CO2 is removed to an absorption liquid tank, and recycling the absorption liquid; condensing the removed CO2 containing a little water vapour by a carbon dioxide cooler, putting the CO2 in a gas and liquid separator to separate high-concentration CO2 and storing the CO2. The method disclosed by the invention has the remarkable advantages of high removal rate, full utilization of the afterheat, energy conservation, low regenerative energy consumption, high regenerated CO2 purity and the like, is easy to amplify, and has quite good application prospect in power plants and other industries.