In recent years, lunar exploration programs worldwide have accumulated a large amount of remote sensing and in-situ observational data, and the latest Chinese mission has returned lunar samples to Earth. The related research continuously advances our understanding of the internal structure and evolution of the Moon. High resolution and precision gravity data from the GRAIL mission have revealed a highly inhomogeneous crustal structure of the Moon, which has been preserved since the early evolution of the planet. In the early 600 Ma of the lunar evolution, external impact events and the internal thermal evolution process together shape the lunar structure, and set the stage for its subsequent geologic evolution. Numerical simulation is a critical tool to backtrack the influence of impact events on the crustal structure and thermo-mechanical evolution of the Moon. This talk will review the current observational constraints on the physical structure and chemical composition of the lunar crust, and explain how the numerical simulation results help us explain the observed structures.