Method for extracting phytic acid serving as active substance of rumex acetosa plant

The invention discloses a method for extracting phytic acid serving as an active substance of a rumex acetosa plant. The method specifically comprises the following steps: (1) cleaning the rumex acetosa plant; (2) crushing the rumex acetosa in warm water through an ultrasonic crushing instrument; (3) crushing by using a crusher, grinding, pouring plant residue liquid generated after grinding into a centrifugal machine, and centrifuging to obtain supernate; (4) adding purified water into the supernatant to form a rumex acetosa mixed solution, and adjusting the pH value of the rumex acetosa mixed solution to maintain the pH value of the rumex acetosa mixed solution at 8; filtering and separating the rumex acetosa mixed solution to obtain rumex acetosa filtrate; and (5) heating and concentrating the filtrate, purifying the concentrated solution, concentrating, and drying to obtain the natural rumex acetosa plant active substance phytic acid. According to the method, the phytic acid in the rumex acetosa plant is