All-optical　modulators　are　crucial　in　optical　communication,　quantum　communication,　and　microwave　photonics,　owing　to　their　low　insertion　loss　and　high　efficiency.　Thermo-optical　modulators,　a　key　subset　of　alloptical　modulators,　have　been　extensively　studied,　particularly　those　based　on　fiber　optics　and　twodimensional　materials.　However,　silicon　photonic　modulators　incorporating　two-dimensional　materials　remain　relatively　underexplored.　This　paper　introduces　a　novel　thermally　induced　phase　shift　model　to　provide　a　deeper　understanding　of　the　effects　of　thermal　phase　shifts　on　waveguide　modes.　A　Mach-Zehnder　interferometric　modulator,　utilizing　graphene　oxide　thin　films　and　silicon　photonic　technology,　was　designed,　fabricated,　and　experimentally　characterized.　The　sensor　exhibited　a　sensitivity　of　0.02127　dB/degrees　C,　with　a　linear　fitting　coefficient　(R2)　of　0.99905　over　a　temperature　range　of　25-55　degrees　C.　Furthermore,　the　phase　modulator　exhibited　a　modulation　efficiency　of　0.03596　rad/mW,　with　a　linear　fitting　coefficient　of　0.99359.　The　proposed　thermal　phase　shift　model　can　serve　as　a　novel　framework　for　designing　and　optimizing　thermal　modulators　based　on　two-dimensional　materials,　offering　valuable　insights　for　future　research　and　development　in　this　field.