<p>Abrasive jet polishing (AJP) is an efficient and precise surface treatment technology suitable for the polishing of semiconductor material surfaces as well as the polishing of complex inner walls and small area micropores. Compared with conventional polishing technology, AJP has the advantages of high efficiency, precision, uniform treatment, no damage and environmental protection, and semiconductor industry, and it is widely used in aerospace, automotive, medical devices and optical instruments. This study introduces the principle and characteristics of complex inner wall abrasive fluid polishing and elaborates on the application of numerical simulation methods, such as simulation, in this technology. Tests and evaluation indices that are commonly used in experimental research are employed, and their advantages and disadvantages are analysed and compared. The highlights of this work include the gas–liquid–solid three-phase coupling theory of AJP, multipipeline simulation and engine air–film fluid simulation. This study analyses the role of the coupling among the three phases of bubbles, abrasive particles and fluids and discusses the flow velocity distribution, pressure distribution, abrasive particle trajectory, surface effects of cavitation bubbles and the effects of the fluids on the polished inner wall during jet polishing. The possible research trends of AJP technology are summarised. AJP is a promising technology for the polishing of complex inner walls and tiny apertures. It provides a reference for researchers in related fields and theoretical basis and technical support for the improvement of the processing quality and efficiency of this technology in practical applications.</p>