Heparin was originally proposed from the liver, and is now mostly extracted from the intestinal mucosa of pigs, sheep, cattle and other animals. It can be extracted from the lungs and liver. Fresh intestinal mucosa was taken and put into the reaction pot. Add sodium chloride at 3% and adjust pH to 9.5 with 40% sodium hydroxide. Gradually raise the temperature to 60-65℃ within half an hour, continue the heat preservation and stirring for 2h, then raise the temperature to 95℃ for 10min, and cool to below 50℃ for filtration. The strongly alkaline quaternary ammonium salt anion resin was added into the filtrate, stirred and adsorbed for 8 hours, and the supersolution was left standing. The next day, siphon off the upper liquid, rinse the resin with water to clarify the liquid, and drain it. Stir it with twice the amount of 1.4m sodium chloride for 2 hours, drain it, and then wash the resin once again without twice the amount of 1.4m sodium chloride. Then, the resin was eluted twice with 3M sodium chloride and dried, the filtrate was combined, the same amount of 95% ethanol was added to precipitate the liquid, the precipitation was collected, and the crude products were dehydrated with acetone. Crude products dissolved in 1% sodium chloride, pHGCF was adjusted with hydrochloric acid 1.7-1.8, filtration. Adjust pH to 11 with 5N sodium hydroxide, add 30% concentration of hydrogen peroxide decolorization, filtration. The filtrate was adjusted to pH 6 with hydrochloric acid and precipitated by adding the same amount of 95% ethanol. Sinidine content with acetone washing, drying, namely heparin.