Objective To investigate the advantages and disadvantages of retrograde arterial approach and transatrial septal approach for radiofrequency ablation of left-sided accessory pathways, and to evaluate the performance of a domestic three-dimensional (3D) cardiac electrophysiological mapping system. Methods From Jul. 2019 to Aug. 2020, 30 patients with supraventricular tachycardia were enrolled in this prospective, randomized controlled study. The left-sided accessory pathways were determined by cardiac electrophysiological examination before operation and all the patients had the indications for catheter radiofrequency ablation. The patients were randomly assigned to retrograde arterial approach group and transatrial septal approach group at a ratio of 1:1. Under the guidance of a domestic 3D cardiac electrophysiological mapping system (Columbus^® system), radiofrequency ablation of left-sided accessory pathways was performed, and the success rate of target mapping, success rate of immediate postoperative ablation, X-ray exposure duration, X-ray radiation dose, operation time and intraoperative and postoperative adverse events were compared between the 2 groups. Results The success rates of target mapping and immediate postoperative ablation were 100% in both groups. The procedure duration ([75.40±22.27] min vs[83.80±39.96]min), X-ray exposure time (384[310, 510]s vs 369[340, 989]s) or X-ray radiation dose (93[63, 123]mGy vs 154[56, 184]mGy) were not significantly different from those of the retrograde arterial approach group (all P>0.05). The incidence of postoperative adverse events was 6.7% (1/15) in the retrograde arterial approach group, and no adverse events occurred in the transatrial septal approach group (P>0.05). The domestic 3D cardiac electrophysiological mapping system could clearly visualize the catheter electrodes. The catheter had good operation performance, could be positioned smoothly, and the attachment was satisfactory. Conclusion The domestic 3D cardiac electrophysiological mapping system can be safely and effectively used for radiofrequency ablation of left-sided accessory pathway ablation. There are no differences in the procedure duration, X-ray exposure time, X-ray radiation dose or incidence of adverse events between transatrial septal approach and retrograde arterial approach.