The invention relates to the technical field of microfluidics and provides a microfluidic chip and an application thereof. The microfluidic chip comprises an upper substrate, a lower substrate, a first porous membrane and a second porous membrane, wherein a first liquid inlet, a second liquid inlet, a first liquid outlet, a second liquid outlet, a first chamber, a second chamber and a first microchannel are arranged on the upper substrate; the second liquid inlet, the first chamber, the second chamber and the second liquid outlet are sequentially communicated through the first microchannel; the lower substrate is provided with a third liquid inlet, a third liquid outlet, a third chamber, a fourth chamber and a second microchannel, and the third liquid inlet, the third chamber, the fourth chamber and the third liquid outlet are sequentially communicated through a second microchannel. According to the microfluidic chip, the four chambers are formed, upper fluid and lower fluid can be subjected to material exchange twice on porous membranes separating the four chambers, so that the blood purification process of glomerular filtration and tubular secretion and reabsorption of renal units can be simulated with high simulation degree.