Stimulated Brillouin scattering is widely used in microwave photonics frequency measurement, however systems based on stimulated Brillouin scattering have long scanning period and low response speed. To improve the scan efficiency, an improved scheme using frequency combs pump and vernier effect was studied. The improved system was analyzed and simulated, and the scanning number was reduced to 7% of the original result under 100 MHz precision and 50 GHz bandwidth. Moreover, when the precision and scanning number are fixed, the improved system has a greater bandwidth which indicates that the property of the system is greatly enhanced.