The field experiment was conducted to investigate the effects of adding decomposed rice husk on the growth of iris and the rhizosphere soil environment. Four treatments were set up in the experiment of turning and burying the decomposed rice husk:control treatment(CK:no decomposed rice husk)，and treatments of decomposed rice husk(T1:0.5 kg·m-2 decomposed rice husks；T2:1.5 kg·m-2 decomposed rice husks；T3:3.5 kg·m-2 decomposed rice husks). Four treatments were set up in the experiment of controlling weeds by covering with decomposed rice hull:control treatment(CK:no decomposed rice hull covering treatment)and treatments of decomposed rice hull covering(A:0.5 kg·m-2 decomposed rice hull covering；B:1.5 kg·m-2 decomposed rice hull covering；C:3.5 kg·m-2 decomposed rice hull covering). The results showed that the addition of decomposed rice husk had a significant effect on the growth and development of iris，and the effects of T1 and T2 treatments were better. Compared with CK，T2 increased by 38.76% and 62.47% in fresh weight aboveground and underground，respectively，after 90 d of planting. When the iris was planted for 120 d in T1，the aboveground fresh weight and underground fresh weight increased by 39.53% and 47.65%，respectively. The characters of iris seed ball were improved，the diameter and dry weight of bulbs in T1，T2 and T3 treatments increased by 18.83%，10.74%，13.97% and 60.40%，53.13%，34.32%，respectively，compared with the control after 120 d of iris planting. However，there was no difference in the number of side balls. In terms of soil environmental indicators，the three treatments reduced the soil compactness significantly. However，the soil pH value decreased and the difference of soil moisture were not significant. In addition，the decomposed rice hull mulching has a good control effect on weeds，which can reduce grass and broad-leaf weeds. Compared with CK，the number of weeds in treatment A，B and C decreased by 11.71%，38.93% and 87.02%，respectively. From the results of control effect，the plant control effect and fresh weight control effect of the three treatments reached 11.43%，38.73%，86.99% and 44.56%，64.13% and 88.78%，respectively. In conclusion，the addition of decomposed rice husk can promote the growth and development of iris and improve the soil environment. The results of this study can provide theoretical guidance for the future research on chemical fertilizer reduction of flowers.