The invention discloses a face cleaning composition with the moisture-preserving function and the skin whitening function and a preparing method thereof. The face cleaning composition is prepared from soybean extract freeze-dried powder, sodium cocoyl glutamate, sodium lauroyl glutamate, bromelain, lipase, dipotassium glycyrrhizinate, pearl powder and chitosan oligosaccharide. The preparing method includes the following steps that 1, raw material soybeans are shelled to be prepared into water slurry and homogenized, (NH4)2SO4 is added, proteins settled when the concentration of the (NH4)2SO4 is larger than 40% and smaller than or equal to 50% are centrifugally collected, emulsion is obtained after concentration, freeze drying is carried out on the emulsion, and the soybean extract freeze-dried powder is obtained and sterilized; 2, the other components are added into the sterilized soybean extract freeze-dried powder according to the quantity of the formula, and the face cleaning composition is prepared. The face cleaning composition is weakly acidic, the skin surface lipid film of the human body is not injured, and the effects of cleaning the skin, locking water, preserving moisture and whitening the skin are further achieved; the preparing method of the face cleaning composition is free from a traditional chemical production adding technology, and the raw materials are natural.