To explore the clinical value of super microvascular imaging (SMI ) and CDFI in evaluating renal perfusion changes in patients with chronic kidney disease (CKD).Methods Seventy-three patients with CKD (146 kidneys) diagnosed at our hospital from March 2020 to January 2021 and thirty-four normal physical examinees (68 kidneys) who performed physical examination in our hospital at the same term were collected as study subjects. According to the K/DOQI staging criteria of CKD, seventy-three patients with CKD were divided into CKD stage 1 group, CKD stage 2 group, CKD stage 3 group, CKD stage 4 group and CKD stage 5 group, a total of 5 groups were set up as case groups, and 34 normal subjects were set up as control groups. CDFI and SMI techniques were used to observe the bilateral renal blood perfusion of all subjects, respectively, and the blood perfusion was graded and recorded.Results Among 214 kidneys, SMI showed grade 4~5 in 157 (73.4%) and grade 0~3 in 57 (26.6%); CDFI showed grade 4~5 in 118 (55.1%) and grade 0~3 in 96 (44.9%);The composition ratio of SMI and CDFI renal blood perfusion grading in the same group was compared, and the differences were statistically significant (P＜0.05 ),and the composition ratio of SMI showing grade 4~5 in the control group and CKD1 stage group~CKD3 stage group was higher than that of CDFI. The composition ratio of SMI grade 3~4 was higher than CDFI in CKD4 stage group and CKD5 stage group. Two-by-two comparison of CDFI renal blood perfusion grading in 6 groups: no statistically significant difference (P＞0.05) between control group and CKD1 stage group and CKD2 stage group, CKD1 stage group and CKD2 stage group and CKD3 stage group, CKD2 stage group and CKD3 stage group, CKD3 stage group and CKD4 stage group, CKD4 stage group and CKD5 stage group, and the rest two-by-two comparison, the difference was statistically significant (P＜0.05). Pairwise comparison of renal blood perfusion grades detected by SMI in 6 groups: there were no statistically significant difference (P＞0.05) between control group and CKD1 stage group and CKD2 stage group, CKD1 stage group and CKD2 stage group, CKD3 stage group and CKD4 stage group, and the rest two-by-two comparison, the difference was statistically significant (P＜0.05). Conclusion The ability of SMI to display renal vessels in different clinical stages of CKD is better than that of CDFI, and it can detect the alteration of renal blood perfusion in CKD at an earlier stage, which is helpful for the clinical diagnosis, disease assessment and treatment of CKD, and can be used as a routine and effective means to evaluate the alteration of renal perfusion in CKD, and has important clinical application value