The invention relates to a pore-level simulation experiment device for alternately displacing oil by microorganisms and air in porous media. The pore-level simulation experiment device comprises a micro-pump, an air pump, a valve, a first intermediate container, a second intermediate container, a third intermediate container, a pressure sensor, a microscopic visualization transparent model, a sampler, a vacuum pump, a bubble tower, a computer, a three-dimensional video microscope, a hot water circulating heater and constant-temperature circulating water bath. The pore-level simulation experiment device has the advantages that remaining oil distribution images can be observed in real time, can be acquired and can be quantitatively analyzed in procedures for alternately displacing the oil by the microorganisms and the air; injection pressures can be measured in real time in the procedures for alternately displacing the oil by the microorganisms and the air; the water content and the oil production of microorganism and air alternative displacement can be metered and analyzed; pore throat characteristics of real oil reservoir rock can be reflected by the designed microscopic visualization transparent quartz sand model, and the model is filled with transparent quartz sand, is convenient to clean and can be refilled with transparent quartz sand to be used.