Abstract: Atomic layer deposition (ALD), a thin-film deposition technology with sub-nanometer precision, is widely used in fields such as integrated circuits, energy, and displays. However, ALD still faces numerous challenges in practical applications, stemming from the multi-process and multi-scale coupling issues caused by the complex fluid dynamics, mass and heat transfer, and surface reactions within the ALD reactor. Numerical simulation helps to reveal the multi-physical/chemical processes and multi-scale coupling mechanisms of ALD, making it a powerful tool for in-depth analysis and optimization of ALD processes. This paper systematically reviews the progress of ALD reactor simulation research, analyzing the thin-film materials, operating conditions, chamber structures, and substrates involved in the simulations. Finally, the challenges faced by current ALD numerical simulation research are discussed, and potential avenues for further optimization of simulation techniques are proposed.