The invention relates to a method for extracting human serum albumin from plasma and increasing the yield. By adoption of the method, the problems of extracting recovered human serum albumin from the plasma and increasing the yield can be effectively solved. The adopted technical scheme is as follows: the method comprises the following steps of: combination and melting of the plasma, preparation and pressing filtration of components I, II and III, preparation and pressing filtration of a component IV, preparation and pressing filtration of a component V, precipitation, dissolving and filtration of the component V, refined purification of the component V, ultrafiltration dialysis and concentration, preparation, pasteur inactivation, bacteria removal and filling, incubation and verification; the preparation and pressing filtration of the component IV comprise the following steps of: adding physiological saline with the temperature of 0 DEG C and the volume of 1/10 of that of the supernatant of the prepared components I, II and III, using acetate buffer solution with pH of 4.0 to adjust the pH value of the solution to 5.80-5.90, adding alcohol with the temperature of minus 15 DEG C and the volume concentration of 95%, and enabling the final volume concentration of the alcohol to reach 40%. The method has the advantages that the production process is smoother and simple, the yield of the human serum albumin is increased and the economic and social benefits are large.