Abstract: Water resources are becoming increasingly scarce worldwide due to population growth and economic development. The overexploitation of groundwater is a global concern, especially in coastal areas where interactions with seawater adds complexity. intensive extraction of subsurface brine in the coastal region of Laizhou Bay, China, has significantly altered the groundwater flow field. However, there is a lack of research on assessing the impact of tides on groundwater levels under such intensive brine extraction conditions. Using frequency analysis and singular spectrum analysis, this study aims to investigate the influence of tidal action on groundwater levels under brine mining conditions using frequency analysis and singular spectrum analysis. The findings demonstrate that brine extraction is the primary factor driving long-term changes in groundwater levels. Both frequency analysis and wavelet coherence analysis confirm that tidal action has a significant effect on groundwater levels, particularly with 12 hour and 24 hour periodic changes. Moreover, different tidal patterns can be accurately identified based on frequency changes. Singular spectrum analysis effectively captures the impact of tidal variations on groundwater levels. The fluctuations in groundwater level caused by tidal changes in the phreatic layer amount to approximately 11.04% of the tide amplitude, accounting for 7.89% of the maximum water level change observed during the study period. Similarly, the fluctuations in groundwater level caused by tidal changes in the first confined aquifer amount to approximately 36.80% of the tide amplitude, accounting for 14.28% of the maximum water level change during the observation period.