Background Transcatheter closure is now the preferred treatment for congenital heart disease complicated with pulmonary arterial hypertension (CHD-PAH), but its long-term effects are not well understood. We aimed to assess the safety, effectiveness, and outcome of this procedure in children with CHD-PAH.Methods We included 210 children with CHD-PAH at our hospital from 2012 to 2021 and collected their general, laboratory, echocardiographic, and hemodynamic data for analysis. A logistic regression analysis identified risk factors for persistent postclosure PAH (PP-PAH).Results Among the 210 patients, 84.29% had mild PAH, 8.57% had moderate PAH, and 7.14% had severe PAH. The device was successfully implanted in 98.10% of patients. Early adverse events occurred in 12.14% (n = 25) of patients, with residual shunts and arrhythmia being the most common complications, each affecting 2.91% (n = 6) of patients. Most complications were minor and temporary, except for two cases of residual shunt-one required surgical repair, and one case of complete left bundle branch block led to occluder removal. Postintervention, pulmonary arterial pressure (PAP) decreased significantly, and cardiomegaly resolved. PP-PAH was detected in 13 patients (6.31%). Preoperative pulmonary arterial systolic pressure [odds ratio [OR] = 1.033, 95% confidence interval [CI] = 1.005-1.061, P = 0.019] and right ventricular diameter (OR = 1.111, 95% CI = 1.039-1.187, P = 0.002) were found to be risk factors for PP-PAH.Conclusion Transcatheter closure is effective and safe for children with correctable CHD-PAH. Preoperative pulmonary arterial systolic pressure and right ventricular diameter are risk factors for PP-PAH.