A dual-channel microwave power detection chip based on MEMS cantilevers is proposed to improve the overload power of thermoelectric microwave power detection chips. By integrating a MEMS fixed-beam with the thermoelectric chip, the design not only protects the thermoelectric chip but also increases its overload power. Theoretical models are established for the capacitive and thermoelectric detection channels, and the sensitivity characteristics and overload power are studied. Test results show that the measured sensitivity of the capacitive channel is 2.21 fF/W, with a theoretical value of 2.24 fF/W, resulting in a theoretical model error of only 1.34%. The measured sensitivity of the thermoelectric channel is 0.03 mV/mW, which aligns with the theoretical value from the model. The overload power model indicates that the chip's overload power can reach 8.77 W. Therefore, compared to a single thermoelectric chip, the dual-channel chip not only achieves high-quality detection of both small and large power signals but also enhances overload power.