Objective: Limestone, a quintessential sedimentary rock, often contains a substantial number of stylolite structures during its formation. This study aims to systematically examine how water immersion affects the tensile creep characteristics of sutures of different widths. The research is critical for enhancing slope stability and underground engineering safety in limestone regions prone to water inundation. Methods: Engineering limestone specimens from Yichang, Hubei Province, were analyzed. Brazilian splitting tests evaluated tensile strength and creep properties under dry and water-immersed conditions. Scanning electron microscopy (SEM) revealed microstructural changes in stylolite components. The conventional Burgers-Mohr rheological model was enhanced by introducing a damage quantity (DEN) to formulate a tensile creep model accounting for water-induced degradation. Numerical simulations validated the model against experimental data. Results: The findings of the experimental investigation demonstrated that water immersion significantly affected the tensile mechanical properties of the stylolite structures. Water-immersed specimens exhibited significantly higher deformation compared to naturally dried specimens. The decline in strength was found to be considerably more pronounced than the corresponding increase in deformation. Specifically, the long-term tensile strength decreased by 28% in specimens with widths b>5 mm. Stylolite structures in limestone are primarily composed of metasomatic dolomite at their center, with stylolite membranes on either side. An increase in stylolite structure width is predominantly reflected in the increase in the concentration of metasomatic dolomite. Following water immersion, the stylolite membranes remain largely intact, while the metasomatic dolomite undergoes erosion. This erosion causes the blurring of crystal edges and an increase in porosity, which is a primary factor determining the extent of mechanical property degradation in the limestone. Wider stylolite structures show greater susceptibility to these effects. The findings of the present study demonstrate that the erosion rate of the metasomatic dolomite specimen following water immersion is closely aligned with the rate of degradation of the specimen's long-term tensile strength. This observation suggests that the erosion rate of the metasomatic dolomite serves as a reliable indicator of the specimen's long-term tensile strength degradation. This study proposes a methodology to assess the degradation of a specimen's long-term tensile strength by measuring the erosion rate of the metasomatic dolomite and linking the erosion of fine-scale structures to the degradation of macroscopic mechanical properties. To achieve this, the conventional Burgers-Mohr rheological model was enhanced by incorporating a damage quantity, DEN, and a tensile creep model accounting for degradation caused by water immersion in stylolite structures for water immersion degradation was formulated. This model was validated through numerical simulations. The simulation results show that the enhanced model provides a more accurate prediction of the specimen's creep behavior. However, the failure time will be marginally shorter than the indoor test value. Nonetheless, the overall trend closely aligns with experimental outcomes and satisfies engineering safety requirements. Conclusions: Metasomatic dolomite erosion rate correlates directly with tensile strength degradation, establishing it as a predictive indicator for limestone durability. The study's methodology links microscale erosion to macroscale mechanical decline, while the enhanced model provides a reliable tool for simulating water-induced creep. The results serve as a reference for calculating the stability of slopes in limestone areas and underground works after inundation.