The invention relates to an extraction method of a heparin sodium crude product, which comprises the steps that a raw material from a fresh pork lung or a thawy pork lung is minced into a pasty material; a cell activator is added for catalysis; biological enzyme enzymolysis, decontamination, separation and filtering are performed; a solution containing heparin sodium is obtained; resin adsorption, elution, organic solvent precipitation and drying are performed; and the heparin sodium crude product is obtained. The extraction method of the heparin sodium crude product can improve the product quality, can increase an effective yield, can lower the production cost, is suitable for industrial production, reduces waste emission, and has social, environmental and economic benefits.