Wellbore stability is critical in oil and gas development, particularly due to shale hydration-induced instabilities. To address this challenge, this study introduces a novel laboratory methodology for real-time, spatially resolved monitoring of hydration-induced strains in shale cores using distributed fiber optic sensors. This technique offers a detailed mapping of hydration strain distribution over time, enhancing our understanding of hydration response characteristics. By employing distributed fiber optic sensing technology, the study overcomes the limitations of conventional monitoring methods and provides precise and efficient capture of the hydration process. The research goes beyond static observations by experimentally monitoring the impact of potassium chloride solutions with varying concentrations on the hydration-induced strain, shedding new light on evaluating drilling fluid performance. The findings reveal that the inhibitory properties of soaking solutions significantly influence shale hydration behavior, with higher inhibitory capacities slowing down the rate of hydration-induced expansion, as evidenced by reduced strain rates or lower strain amplitudes. Moreover, the non-uniform distribution of hydration strain across different monitoring points highlights the heterogeneous nature of shale surface hydration. The presence of rock fractures, particularly in Core 2, affects strain measurement and can lead to the observation of negative strains in the hydration strain waterfall plot. This information is crucial for interpreting the dynamic shifts in shale properties amid hydration and evaluating the inhibitive effectiveness of drilling fluids.