Visualization monitoring methods with high depth resolution for the curing process are of great significance for in-depth understanding of polymer curing kinetics and optimizing curing processes. In recent years, two types of functional optical coherence tomography (OCT) techniques based on digital image correlation (DIC) and phase-sensitive detection (PhS) have been developed internationally. With the advantages of non-contact, high-resolution and real-time monitoring, these techniques have become effective means for polymer curing monitoring. However, current research still presents two main limitations. First, there is a lack of systematic quantitative comparison between the two methods in practical scenarios. Second, PhS-OCT is restricted by the 2π phase wrapping effect, making it difficult to meet the monitoring requirements under large deformation conditions. To address the above problems, this study quantitatively compares the differences between DIC-OCT and PhS-OCT in measurement sensitivity, range and noise immunity, and clarifies the applicable boundaries of the two techniques. On this basis, an adaptive frame interval adjustment method based on phase gradient is innovatively proposed. By constructing a dynamic regulation mechanism of "phase gradient-signal-to-noise ratio coupling", the monitoring frame interval is dynamically adjusted to achieve collaborative optimization of measurement range expansion and cumulative error suppression. To verify the effectiveness and practicability of the proposed method, curing experiments of double-layer composite resin and simulated dental restoration experiments are carried out respectively. In the double-layer resin experiment, the monitoring range of PhS-OCT is successfully expanded from -12.21 mε to -22.15 mε, and the computational efficiency is improved by 24 times compared with the traditional incremental method. In the complex noise environment of enamel with high-reflection speckles, the proportion of invalid strain calculation regions of DIC-OCT reaches 16.8%, while the proposed method achieves reliable monitoring of the whole resin curing process relying on strong noise immunity and dynamic range expansion capability. After deep integration with PhS-OCT, this method realizes high-precision, large-deformation and full-field dynamic monitoring of polymer curing process.