The invention discloses a long-acting compound herbicide and a preparation method thereof. The long-acting compound herbicide is prepared from, by weight, 40-50 parts of
solvent, 8-18 parts of
acetochlor, 4-9 parts of lactofen, 8-15 parts of 2,4-D butyl ester, 8-15 parts of cyclohexanedione, 5-10 parts of
trichloroacetic acid, 3-10 parts of methylated
soybean oil, 9-16 parts of
nitrophenol, 10-18parts of
bensulfuron methyl, 5-10 parts of clodinafop-
propargyl, 4-6 parts of antifoaming agent, 10-20 parts of butralin, 3-5 parts of surfactant and 1-6 parts of
thickening agent. According to the long-acting compound herbicide, different weeding mechanisms are used for killing
weed, therefore, the resistance generation speed of the
weed is reduced, and the weeding activity of the long-acting compound herbicide is greatly improved; the long-acting compound herbicide is used through compounding, the weeding spectrum is enlarged, the number of herbicide application times and the herbicide
application time are reduced during application, and the long-acting compound herbicide is simple in usage method, quickly becomes effective and has significant effects.