A multi-beam interference optical fiber Fabry-Perot probe for pulsating micro-pressure sensing is proposed in this article. The probe′s multi-beam interference wavelength drift and micro-pressure sensing models are formulated, and the micro-pressure sensitivity difference between gas and liquid environments is analyzed. The optical fiber probes are fabricated by chemical corrosion, electric discharge welding and precision cutting technology. The micro-pressure sensing environment is set up using medical syringe, transparent flexible hose, and quartz ferrules. The internal pressure distributions are analyzed by finite element simulation. Three optical fiber FP probes are measured under the gas pressure from 14. 41 to 85. 22 kPa and the liquid pressure from 4. 50 to 26. 02 kPa. Experimental results show that in both gas and liquid environments, the probe wavelength has a red-shift with the pressure increase, and a blue-shift with the pressure decrease. The probe′s average micro-pressure sensitivity in gas environment can reach 8. 210 pm·kPa -1 . In liquid environment, it can reach 66. 720 pm·kPa -1 , which is higher and is consistent with the theoretical prediction. The optical fiber FP probe featuring the highest micro-pressure sensitivity in both gas and liquid environments is selected for the liquid pulsating micropressure sensing measurement. Experimental results show that the probe has good wavelength response and the repeatability error is small within five pulsating cycles. The optical fiber FP probe proposed in this article has the advantages of compact structure, easy fabrication,and high micro-pressure sensitivity. It can realize pulsating micro-pressure sensing in the frequency range of 1 Hz, which provides an important reference value for micro-pressure sensing applications in liquid environment.