Methyl oxalate is a fused heterocyclic, selective post-emergence herbicide, suitable for controlling broad-leaved weeds in corn and soybeans. Field efficacy tests show that 5% oxalate methyl vinegar EC has good pesticide control effects on annual broad-leaved weeds (such as Lebanon, Rhizoma rotundifolia, Serratia vulgaris, Jianma, etc.) of spring corn and soybean. Dosage: 7.5-11.5g of active ingredient per hm2 (in Northeast China () converted into 5% milk oil, the commodity amount is 10-15ml1667m2); in the 3-5 leaf stage of spring corn, and 1-2 compound leaf stage of soybean, the dosage is according to the dosage Spray the stems and leaves after dilution with water; it is safer for spring corn and soybeans. For fields where broad-leaved weeds and gramineous weeds are mixed, they should be used with pesticides for controlling gramineous weeds.