The invention relates to an extraction technology of crude heparin sodium. The extraction technology comprises the following steps: hydrolysis: putting broken raw materials into a reaction kettle, adding a hydrolysis liquid into the reaction kettle, adding resin into filtrate, stirring, siphoning the supernatant liquid, collecting the resin, washing the resin in clean water till the resin is neutral, and draining; desorption: soaking the resin with dilute saline water, discarding the soaking solution, adding concentrated saline water into the resin twice, stirring, washing, filtering, and keeping the washing liquid; alcohol precipitation: adding ethyl alcohol into the washing liquid, stirring, carrying out standing, discarding the supernatant liquid, keeping the bottom sediment, draining the sediment, adding ethyl alcohol, washing, unwatering, and collecting dehydrated heparin sodium sediment; drying: drying the heparin sodium sediment in vacuum. The extraction technology of crude heparin sodium provided by the invention has the following advantages: all the steps are clear, so that labor division and cooperation are facilitated; the contents of various important additives have quantitative marks and are authenticated through tests, and the sequence among the additives is clear.