In order to study optimum planting depth of rice pot seedling machine on ratooning rice production of South Henan province, we chose Liangyou 6326 as research materials and set five different planting depths. The results showed that when transplanting depth is too shallow, easy to drift seedling lodging, affecting the quality of transplanting, mature period easy lodging, affecting output. The deeper the rice is planted, the slower it is turn to green and tillering. If the depth of planting is too deep, it is easy to produce dead seedlings, and the tiller rate of seedlings is reduced, and the effective panicle population is lost too much, which reduces the yield. The effective panicle number and grain number per panicle were the main factors affecting yield under different planting depth.When the planting depth was 2 cm, the yield of first season rice and regrowth rice was the highest of 12 777 kg/ha.