<p>The mechanical and optical properties of nanometer titanium dioxide (TiO₂) and polydimethylsiloxane (PDMS) composites are critical in applications such as microfluidics, sensors, optical systems, and biomedicine. However, the precise control of TiO₂/PDMS properties through synthesis parameters and processing conditions remains a significant challenge. This paper presents a fabrication strategy for TiO₂/PDMS composites with customizable opto-mechanical properties. Polarization-sensitive optical coherence elastography is employed for the systematic characterization of these properties. By conducting both single-factor and multi-factor analyses, a comprehensive polynomial model was developed, establishing correlations between curing ratio and curing temperature, with Young's modulus, and stress optical coefficient, achieving a goodness of fit exceeding 0.95. Leveraging these insights, a straightforward and reproducible fabrication process for TiO₂/PDMS samples with tunable and quantifiable opto-mechanical properties was developed. Additionally, a TiO₂/PDMS-based breast tumor tissue-mimicking phantom was designed and quantitatively characterized, achieving opto-mechanical properties and stress distribution measurement errors below 6%. This study not only advances the understanding TiO₂/PDMS composite materials, but also expands their potential the applications in optical imaging and biomedical engineering.</p>