The invention relates to single light source excitation vibration meter based on sinusoidal phase modulation. Its structure is as follows: the light source is driven by modulation driving source; isolator, coupler, and collimator are orderly set along the emitted light traveling direction; they are connected by optical fiber section; the output of the first optoelectronic converter is connected with the input of the first preamplifier; the output of the second optoelectronic converter is connected with the input the second preamplifier; the output of the modulation signal, the first and second preamplifier are respectively connected with the first, second, third inputs of the data processor of which output is connected with signal monitor. The invention has simple structure, easily realizes micro resonator light-heat excitation, and measures the tested resonating body frequency and vibration amplitude with high precision at the same time.