Objective To observe the efficacy of compound sulfadiazine zinc gel in the treatment of venous leg ulcers. Methods Patients with venous leg ulcer were selected in our hospital from Jan. 2015 to Dec. 2019, including 40 outpatients with dressing change without surgical treatment and 40 patients with surgical treatment. The outpatients were randomly divided into non-surgical experimental group (n=20) and non-surgical control group (n=20), and the patients with surgical treatment were divided into surgical experimental group (n=20) and surgical control group (n=20) by random number tables. Compound sulfadiazine zinc gel was applied to the leg ulcers after routine iodophor dressing in both experimental groups, while rivanol gauze was applied in both control groups. The ulcer area reduction rate and the ulcer healing rate in each group were observed and compared at different time points. Results The ulcer area reduction rates in the non-surgical experimental group were significantly higher than those in the non-surgical control group after 1, 2, and 3 weeks of treatment (all P<0.01). The ulcer area reduction rates in the surgical experimental group were similar to those in the surgical control group after 1, 2, 3, and 4 weeks of treatment (all P>0.05). There was no significant difference in the healing rate between the surgical experimental group and the surgical control group at 2 or 4 weeks of treatment (both P>0.05). The ulcer healing rate was 0 in the non-surgical experimental group and 5% (1/20) in the non-surgical control group after 3 weeks of treatment, with no significant difference between the two groups (P>0.05). Conclusion Compound sulfadiazine zinc gel can promote the healing of venous ulcers in the lower limbs. In patients with conservatively treated venous ulcers receiving no surgery, the efficacy of external application of compound sulfadiazine zinc gel is better than that of rivanol after routine dressing change.