A simple approach to generate stable microwave signals by heterodyning pump light and Stokes lasing light from a dual-wavelength Brillouin fiber laser (BFL) is proposed and demonstrated. Stable dual-wavelength output is obtained by adjusting two polarization controllers. A microwave signal is observed and the central frequency of the microwave signal is around 10.75 GHz. A segment of 10 km-long single-mode fiber (SMF) is used as Brillouin gain, and a 4 m long unpumped polarization maintaining erbium-doped fiber (PM-EDF) and micro-ring cavity, which is composed of 2×2 3 dB coupler, suppress unwanted side-modes. A distributed feedback (DFB) semiconductor laser is used as the Brillouin pump (BP). The output of dual-wavelength fiber laser is injected into a optoelectric detecter (PD) with a bandwidth of 50 GHz. An electrial spectrum analyzer (ESA) is used to measure the microwave signal around 10.75 GHz. Linewidth of the microwave signal is around 600 kHz.