Objective To investigate the clinical implications and application value of triglyceride-glucose (TyG) index in late recurrence after radiofrequency catheter ablation (RFCA) in the non-diabetic patients with persistent atrial fibrillation (PeAF). Methods The clinical data were retrospectively reviewed of 242 non-diabetic PeAF patients, who received RFCA for the first time at Cardiology Department in Seventh People′s Hospital of Zhengzhou and Henan Provincial Chest Hospital from January 2020 to August 2021. The patients were regularly monitored for recurrence at 1,3, 6 and 12 months following the procedure, and according to recurrence within 3-12 months, they were divided into non-recurrence group (n=190) and recurrence group (n=52). Statistics and graphics were performed using SPSS statistics 26.0 and GraphPad 9.0. Depending on data type, t test, Mann-Whitney U test, χ² test or adjusted χ² test was used for comparison between groups. Multifactorial Cox regression was used for analyzing independent risk factors for late recurrence and the predictive value of TyG index for postoperative recurrence in the non-diabetic PeAF patients. Results The recurrence group had a longer PeAF history with a higher tendency to develop coronary artery disease (CAD), a significantly larger left atrial diameter (LAD), a higher TyG index, and a higher proportion of patients not treated with angiotensin receptor neprilysin inhibitor (ARNI) (P<0.05). PeAF history, CAD, LAD, postoperative ARNI treatment and TyG index were independent risk factors for recurrence (P<0.05). Non-diabetic PeAF patients with higher TyG index were more prone to recurrence. Conclusion TyG index has a good predictive value for late recurrence after RFCA in non-diabetic PeAF patients, providing significant guidance for their comprehensive management.