Abstract: In order to improve the accuracy of microwave power measurement, the linear relationship between the direct current component of the Hall voltage and the microwave power density is obtained by analytical method when a planar electromagnetic wave acts on a Hall device. Two types of microwave power detectors, namely the through type and the absorption type, are designed based on the coaxial line. Taking the coaxial through type as an example, the linearity of the detector reaches 98. 28% when the power is between 0.1 mW to 50.0 mW, the rise time is 3 μs~6 μs, and the frequency range is 1 GHz~10 GHz. The experimental results agree well with the theoretical analysis ones. The new detectors have both the characteristics of good linearity and fast response and are expected to be more widely used.