Objective：To evaluate the feasibility of interventional closure in migraine patients with moderate right -to -left shunt patent foramen ovale（RLS-PFO）by comparing the surgical difficulty and short-term efficacy between patients with moderate or large RLS-PFO. Methods：A total of 95 patients with migraine accompanied by moderate or large RLS-PFO who underwent interventional closure were selected. The differences inmigraine symptoms，closure success rate，closure difficulty，postoperative RLS volume and postoperative headache relief level were analyzed. Results：There was no significant difference in preoperative headache impact test-6 （HIT-6）and migraine disability assessment questionnaire（MIDAS）scores between the two groups（P＞0.05）. There was no difference in closure success rate between the two groups（92.00% vs. 98.57%，P=0.137），but the usage rate of the second guidewire，intracardiac ultrasound utilization rate，and X-ray exposure time were significantly higher in the moderate RLS-PFO group than in the large RLS- PFO group（P < 0.01）. The effective closure rate at 3 days after the procedure was higher in the moderate RLS-PFO group than in the large RLS-PFO group（86.96% vs. 56.52%，P=0.008），but there were no differences in RLS volume and effective closure rate at 1 month，3 months and 6 months after operation between the two groups（P＞0.05）. The HIT-6 and MIDAS scores were improved at 6 months after the procedure compared to before the procedure in both groups（P<0.001），but the decrease in HIT-6 score at 6 months after the procedure was smaller in the moderate RLS-PFO group than in the large RLS-PFO group（P=0.012），while there was no difference in MIDAS score. Conclusion：The surgical difficulty of interventional closure in migraine patients with moderate RLS-PFO is higher than in patients with large RLS-PFO，but the efficacy of headache relief after interventional closure is similar between the two groups.