Provided is an optical micro-electro-mechanical system (MEMS) based monitoring system, comprising: a broadband light source, a tunable optical filter (TOF), an optical etalon, a plurality of optical receivers, a plurality of optical couplers, and a plurality of optical MEM sensors; the TOF is configured to capture a transmission, reflection or interference spectrum of the optical MEMS sensors; wherein the peak or depression wavelength in the transmission, reflection or interference spectrum corresponds to a parameter of the pressure, temperature or stress, and the peak or depression wavelength can be obtained by comparing the spectrum with the periodic spectrum of the optical etalon, the optical etalon has an absolute wavelength mark; and the optical MEMS sensor comprises an optical MEMS resonator. The parameter of the pressure, temperature or stress can be obtained by the peak or depression wavelength in the transmission, the reflection or the interference spectrum of the optical MEMS sensor.