Objective To observe the effect of Euphorbia humifusa on expression of nephrin, desmin, and Angptl4 in glomerular podocytes of diabetic kidney disease (DKD) rats, and to clarify the mechanism of its action in DKD treatment. Methods Eight-week-old male SD rats were randomly divided into normal (N), DKD group (D) and DKD treated with Euphorbia humifusa (E) groups. Rats in D and E groups were treated by a single tail vein injection of 55 mg/kg streptozotocin to induce the DKD model. Rats in the N group were injected with the same volume of citrate buffer. The DKD model was evaluated by 24 h urinary albumin of >5 mg/ d for 3 consecutive detection. After 5 weeks, the DKD model was established in 10 D group rats and nine E group rats. After successfully establishing the DKD model, the E group was administered 300 mg/ (kg·d) Euphorbia humifusa by gavage, and rats in D and N groups were administered the same volume of double distilled water by intragastric administration for 16 weeks. All rats were weighed before death, urine was collected to measure 24 h urinary albumin, and blood was collected for serum albumin, urea nitrogen, creatinine, cholesterol, and albumin measurements. Hematoxylin-eosin and Masson trichromatic staining were used to observe the nephrotic structure. Podocyte morphology was observed by transmission electron microscopy. Podocytes were labeled by WT1 staining and counted by the dissector/ fractionator method. Protein localization of nephrin, desmin, Angptl4, and WT1 was observed by immunohistochemistry. Western blot was used to measure the protein expression levels of nephrin, desmin, Angptl4, and collagen IV. Nephrin, desmin, Angptl4, and collagen IV mRNA expression was measured by qPCR. Results Compared with the findings in the N group, in the D group, blood glucose, 24-hour urine albumin, urea nitrogen, creatinine, and cholesterol were significantly increased, while albumin was significantly decreased. All indexes in the E group were significantly improved compared with those in the D group (P<0. 05). Hematoxylin-eosin and Masson staining showed that the glomerular structure of rats in the N group was complete without obvious mesangial hyperplasia. In the D group, mesangial hyperplasia and mesangial matrix deposition were observed. In E the group, these conditions were improved by intragastric treatment with Euphorbia humifusa. Transmission electron microscopy showed that glomerular podocytes of the N group were normal, podocytes of the D group were fused or disappeared, and podocytes of the E group were intact. WT1 staining showed that the number of podocytes in the D group was lower than that in the N group, and the podocytes number in the E group was significantly higher than that in the D group (P<0. 05). Immunohistochemistry, western blotting, and qPCR showed that protein and mRNA expression of desmin, Angptl4, and collagen IV in the N group were lower than those in the D group, while protein and mRNA expression of desmin and Angptl4 in the E group were significantly lower than those in the D group (P<0. 05). Nephrin protein and mRNA expression in the D group was significantly lower than that in the N group, and nephrin protein and mRNA expression in the E group was higher than that in the D group (P<0. 05). Conclusions Euphorbia humifusa treatment significantly reduces the expression of desmin, Angptl4, and collagen IV, and increases the expression of nephrin in DKD rat podocytes. Euphorbia humifusa effectively protected the mechanical and charge barrier of podocytes, inhibits transdifferentiation of podocytes, reduces proteinuria, and improves renal functions.