A CMOS-MEMS humidity sensor includes a complementary metal oxide semiconductor (CMOS) ASIC readout circuit and a microelectromechanical system (MEMS) humidity sensor. The MEMS humidity sensor is provided on the ASIC readout circuit. The ASIC readout circuit includes a substrate, a heating resistor layer located above the substrate, a metal layer located above the heating resistor layer, and dielectric layers. The substrate, the heating resistor layer, and the metal layer are partitioned by dielectric layers. The MEMS humidity sensor includes an aluminum electrode layer, a passivation layer located above the aluminum electrode layer, and a humidity sensitive layer located above the passivation layer. The provision of heating resistors in the ASIC circuit realizes the heating function and satisfies the requirements of the standard CMOS process, so that the CMOS-MEMS integrated humidity sensor can be used stably under low temperature and high humidity conditions.