Aiming at the requirement of miniaturization of Brillouin analog signal processing system, this paper presents a stimulated Brillouin scattering instantaneous frequency measurement(SBS-IFM) scheme based on the doped silica waveguide. In this scheme, the reflected light is effectively filtered out, and the Brillouin gain signal in the doped silica waveguide is amplified and observed by adding a lock-in amplifier and a filter. SBS-IFM based on the doped silica waveguide is realized by relatively moving the modulation frequency of pump light and the probe light, the IFM range of this scheme is about 15 GHz and the accuracy can reach 60 MHz.