Abstract: In order to explore the application technology of pentoxazone in direct-seeding rice fields, the control spectrum, biological activity, and safety of pentoxazone to eight varieties of rice were determined in the greenhouse, and its control efficacy in the field was verified. The results showed that when the dose of the active ingredient was 225 g/hm², the inhibition rates of pentoxazone on fresh weight of five kinds of weeds including Eleusine indica, Cyperus difformis, Eclipta prostrata, Cyperus rotundus, and Cyperus iria were all more than 90%, and the GR₅₀ (active ingredient, the same as the rest) of pentoxazone on main weeds such as Echinochloa crus-galli, Digitaria sanguinalis, E. prostrate, and C. iria were between 82.15 g/hm² and 189.17 g/hm². The safety results showed that when the dose of the active ingredient was 1800 g/hm², it was safe for the eight tested rice varieties, with plant height inhibition rates of 1.89%-5.16%, and fresh weight inhibition rates of 1.47%-4.14%. The selectivity indexes of pentoxazone between four rice varieties Longliangyouhuazhan, Ziliangyou 5, Nanjing 9108, Nanjing 46, and four weeds E. crus-galli, D. sanguinalis, E. prostrate, C. iria were 3.27-28.24, and its selectivities between rice and E. prostrate, and C. iria were significantly better than that of oxydiazon. At 450 g/hm² of the active ingredient and 45 days after field application, the fresh weight control effect of pentoxazone on weeds in direct seeding paddy fields was 87.94%. The results showed that pentoxazone has good application prospects in direct-seeding rice fields.