Abstract: To solve the problem of seeding machine which with a drum or a vacuum suction for seeding can not be used in float seedling planting of oriental tobacco，seeding mechanism was designed.Number of planting hole sowing on stick was reduced，so that processing difficulty was reduced.Protective device for mechanical rotary seeding machine was canceled，so that maintaining difficulty of process was reduced.Seeding mechanism and acupoint pressing mechanism were driven by a stepping motor.Precise control of seeding process was realized by SCM.Planting precise was achieved and seeding precision was improved.Experiments showed that running of improved seeding mechanism was stable，production efficiency was 125 disch，vacancy rate was 0.89%，pass rate of seeding was 99.1%，seed damage rate was 0.51%.Need of production was met.The improved seeding machine has been widely applied in oriental tobacco planting region of Baoshan city in Yunnan province.