Since the introduction of microfluidic technology, its application has spanned many disciplines and fields. Among them, the micro-displacement technology using visual micro-model to simulate real reservoir rock pores has shown extraordinary application value and development potential in recent years. Compared with the traditional macroscopic core flooding experiment, this method shows many advantages. In particular, it realizes the visualization of multiphase flow in pores so that researchers can study the microscopic mechanism of oil displacement. Nano-oil displacement method has been widely concerned and applied in tertiary oil recovery in recent years. The unique physical and chemical properties brought by the small size of nanoparticles make them play a role in various mechanisms in rock pores. By combing the microscopic nano-oil displacement experiments carried out by many scholars using microfluidic equipment in recent years, the microscopic mechanism of nano-oil displacement mainly includes : wettability change, reduction of interfacial tension (IFT), improvement of mobility ratio, and stabilization of asphaltene. At the same time, the main control parameters affecting the effect of nano-oil displacement are summarized. With the development and improvement of related technologies, the application of microfluidic methods provides a more advantageous platform for the exploration of the microscopic mechanism of nano-oil displacement and the optimization of control parameters.