Abstract: With the development of high-end manufacturing, precision instruments have become indispensable equipment in various fields, but due to the existence of environmental micro-vibration makes the precision of the equipment decline, so it is important to carry out micro-vibration level measurement. Micro-vibration level measurement using velocity signal octave spectrum, and the traditional octave analysis using frequency domain FFT has a fixed resolution, low-frequency band spectrum leakage and other shortcomings, in order to address this issue, a complex analytical ZFFT refinement correction algorithm based on the ratio correction is proposed, simulation results show that the algorithm in the same number of points of the FFT analysis, spectrum resolution is improved, in the same number of samples, the amount of computation is greatly reduced, and spectrum amplitude error is low. The simulation results show that the algorithm can improve the spectral resolution with the same number of FFT analysis points, reduce the computation volume significantly with the same number of sampling points, and reduce the spectral amplitude error to as low as one thousandth. On the basis of this algorithm, a split-band octave spectrum analysis is adopted to suppress the leakage of low-frequency spectrum and achieve the directional increase of spectral lines. A micro-vibration monitoring and analysis system, including low-frequency micro-vibration sensors, MI-7208 intelligent measuring device and micro-vibration level measurement and evaluation software, has been developed. Through the measurements on the vibration-isolated foundation of the ultra-clean room of the ZHIJIANG LAB and the outdoor site, the results show that the system has the ability of detecting micro-vibration signals of the VC-F level, and has the stability of the measurement in a long period of time.