Thiazulon is a selective herbicide after seedling, which is an inhibitor of branched-chain amino acid synthesis. It can inhibit the biosynthesis of valine, leucine and isoleucine, prevent cell division and stop the growth of sensitive crops. Mainly used in the control of grain crops wheat, barley, oats, corn field of broad-leaved weeds, such as back branching amaranth, purslane, sowerwort, shepherd's purse, pighair cabbage, pig plague, mother Na, bovine root, etc., to acickle, field flowers and grass, such as ineffective. From 2 leaf stage of wheat and barley to 2 ~ 4 leaf stage of weeds, 75% dry suspension 0.25 ~ 0.41g/100m2, 4.5kg of water, 0.2% of the liquid amount of non-ionic surfactant was added, and the stem and leaves were sprayed.