Fabricating host-guest composites based on the combination of porous metal-organic frameworks (MOFs) and fluorescent dyes is appealing for ratiometric luminescent thermometry. Herein, we design a NbO-type MOF, which has a 3D architecture established by a tetracarboxylic ligand containing π-conjugated naphthalene moiety and Zn2+ ions via solvothermal conditions. The considerable regular channels enable the guest molecules Rhodamine B (RhB) to be quickly absorbed. The composite RhB@MOF formed by ion-exchange was further explored the temperature sensing behavior in the physiological temperature range. RhB@MOF exhibits an excellent linear relationship between the luminescent intensity ratio of the organic linker and the dye RhB and temperature in the range of 30–90 °C, with the maximum relative temperature sensitivity (Sr) of 0.42%·oC−1 at 30 °C. These results validate the potential of this thermal-responsive material for sensitive temperature detection and further promote the development of ratiometric thermometers working in the physiological temperature range.