Objective To explore the effects of step-ball exercise on lower limbs deep venous hemodynamic parameters in postoperative patients with gynecologic malignancies, and to provide reference for preventing lower limbs venous thrombosis in clinic. Methods Totally 40 postoperative patients with gynecologic malignancies were randomized into a control group and an experimental group, with 20 patients in each group. Based on routine treatment and nursing, the patients in the control group were instructed to do ankle pump exercise after anesthetic awareness, while the patients in the experimental group were guided to do step-ball exercise. The maximum blood velocity and mean blood velocity of femoral vein were observed for the two groups before and after the first exercise and the 3rd day after surgery. Results There were no significant differences in the maximum blood velocity and the mean blood velocity of lower limbs between the two groups at different time points （P＞0.05 for all）.Anovariance analysis of single-factor repeated measurement within group indicated that, there were significant differences in the maximum blood velocity and the mean blood velocity before and after exercise for the two groups （P＜0.01 for both）. The maximum blood velocity and the blood velocity of lower limbs vein immediately and 30 minutes after ankle pump exercise or step-ball exercise were significantly higher than those in resting state （P＜0.01 for all）. Conclusion Step-ball exercise at an early stage for postoperative patients with gynecologic malignancies can increase lower limbs blood velocity, promote lower limbs blood reflux, which could replace ankle pump exercise in part or be used as a useful substitution for ankle pump exercise, and as an intervention measure to prevent lower limbs thrombosis.