This study focuses on the southeastern coastal region of China, investigating the relationship between sea level anomalies (SLA) and ENSO events, to elucidate the dynamic mechanisms driving regional sea-level variations under the background of global warming. Using tide gauge records from Kanmen and Quarry Bay and NCEP reanalysis wind field data, we analyzed relative sea-level trends from 2000 to 2020. According to the results, the study region’s yearly mean rate of sea-level rise is roughly 4.24 mm, which is far greater than the national average. It is also marked by low-frequency oscillations and strong seasonality. Further analyses reveal a significant negative correlation between SLA and the Southern Oscillation Index (SOI) (r = − 0.59), exhibiting strong synchronicity without time lag. Zonal wind speed also shows a synchronous negative correlation with SLA. In contrast, the strongest negative correlation between meridional wind speed and SLA occurs with a two-month lead, suggesting its potential role as a precursor of SLA variations. The findings suggest that ENSO events affect sea level anomalies along the southeastern coast of China by altering the regional wind field, particularly the meridional component, making ENSO a major meteorological driver of SLA variability in this region.