Mixed herbicide containing flazasulfuron, dithiopyr and trifluralin

The invention discloses a mixed herbicide containing flazasulfuron, dithiopyr and trifluralin. The herbicide is prepared by taking flazasulfuron, dithiopyr and trifluralin as main effective components, wherein the mass ratio of flazasulfuron to dithiopyr to trifluralin is (0.1-80):(0.1-80):(0.1-80). The mixed herbicide can be applied to weeding before seedling emergence of a lawn and is particularly remarkable in effect when being applied to prevention and control of various grass families, sedge families and broad leaf weeds in the lawn. The mixed herbicide is relatively high in synergistic effect, capable of delaying the weed resistance, wide in weeding spectrum, long in lasting period and safe to the lawn; and the effect of the mixed herbicide is remarkably higher than that of a single herbicide.