Microwave frequency measurement is an important part of electronic warfare systems. The electric field frequency measurement method has disadvantages of bulky system volume, high power consumption and weak immunity to electromagnetic interference, and the light auxiliary frequency measurement method has defects of either wide frequency range with low-resolution or high-resolution in narrow measurement range. We propose and experimentally demonstrate an instantaneous microwave frequency measurement method with wide range and high resolution based on dual polarization modulation. This method measures in a large range of microwave frequency with a relatively low resolution, and then in a small range with high resolution. The experimental results show that this method can achieve instantaneous frequency measurement resolution better than ±0.14 GHz in 2.7~19.4 GHz range.