Diquat dibromide is a non-selective contact herbicide with certain conductivity, which can be absorbed by the green tissues of weeds. Weeds begin to die within hours of being treated. The medicinal liquid has no adverse effect on mature and brown bark, and the medicinal liquid is passivated after contacting the soil. Under normal technical conditions, it does not affect the germination and emergence of seeds in the soil, and basically has no destructive effect on the underground rhizomes of plants. Prevention of v