In this experiment, the effects of 13 kinds of herbicides (or mixtures) on the control of two kinds of weeds were studied by pot cultivation with the broadleaf weed Malachium aquaticum L. and Gramineae weed Poa annua L. as the materials. The results showed that the herbicide MCPA-Na had the best and fastest control effect on Malachium aquaticum L., and all the Malachium aquaticum L. died 7 d after treatment; it was followed by the other four herbicides including MCPA-Na+clethodim, MCPA-Na+ quizalofop-p-ethyl, bentazon and nicosulfuron·atrazine, and all the Malachium aquaticum L. died 14 d after treatment. Atrazine was the best herbicide to control Gramineae weeds, followed by nicosulfuron·atrazine, and mesotrione·nicosulfuron·atrazine. The study on the application of field herbicide found that four herbicides including atrazine, mesotrione·nicosulfuron·atrazine, nicosulfuron·atrazine and bentazon had better control effect on weeds. The best herbicide for flax field was MCPA-Na + clethodim, followed by MCPA-Na and MCPA-Na + quizalofop-p-ethyl. The optimized herbicides and combinations had no harmful effects on the growth of corn and flax.