Optical　pressure　sensors　have　the　advantage　of　being　impervious　to　electromagnetic　interference.　However,　it　remains　difficult　to　explore　the　quantitative　relationship　between　the　optical　response　and　the　exerted　applied　pressure.　Here,　for　the　first　time,　the　quantitative　relationship　between　the　deformation　of　optical　resonator　and　the　applied　pressure　and　the　optical　response　characteristics　of　the　structure　are　investigated　in　detail　by　finite　element　method,　and　an　ultracompact　optical　pressure　sensor　with　a　high　sensitivity　similar　to　10.2　nm/MPa　is　demonstrated.　Simulation　results　show　that　the　maximum　deformation　of　the　optical　resonator　is　linearly　related　to　the　applied　pressure　and　has　a　limit　value　at　a　fixed　input　pressure　as　the　range　of　pressure　applied　increases.　The　results　also　imply　that　the　external　force　can　induce　a　redshift　in　the　resonance　wavelength　in　addition　to　generating　intriguing　phenomena　like　Fano　resonance.　These　observations　contribute　to　the　enhancement　and　diversification　of　the　optical　response　within　the　system.　The　special　features　of　our　suggested　structure　are　applicable　in　optical　property　change　detection　under　different　pressures,　chemical　high-pressure　experimental　measurement,　and　study　of　chemical　reaction　kinetics　process.