The invention discloses a preparation process for extracting human fibrinogens from waste for extracting cryoprecipitated blood coagulation factor VIII. The preparation process is characterized by comprising the steps of cryoprecipitation dissolution, 2% aluminium hydroxide gel absorption, ion strength adjustment, series connection filtering, S/D viral inactivation, ion-exchange chromatography, EDTA Ca2+ removal, glycine precipitation, primary low-temperature ethanol precipitation, AT-III thrombin inhibition, secondary low-temperature ethanol precipitation, nanofilm filtering and dry-heat inactivation. For ensuring the safety, a nanofilm ia added to filter virus except S/D and dry-heat inactivation. By means of an added AT-III inactivated thrombin and EDTA Ca2+ removal process, fibrinogen in the production process is effectively prevented from being activated into fibrous protein. The glycine precipitation is utilized to remove fibrous protein monomers and polymers in products so as obtain high-purity human fibrinogen. The preparation products are safe and reliable, redissolution time is short, the clinic first-aid demand is met, and meanwhile the preparation process has important significance on indirect saving of scarce plasma resources.