Augmented reality (AR) enhances an operator’s capacity to perceive information by superimposing visual assembly process instructions onto the workbench. This technology significantly improves the quality and efficiency of complex product assembly, such as in aerospace industries, while also reduces cognitive load on operators. This paper initially examines and discusses key technologies in current AR assembly, including tracking, human–computer interaction, and display. Subsequently, it systematically reviews the research and application status of AR assembly for existing aerospace products from three perspectives: Head-mounted AR, handheld AR, and projection AR, and this paper also explores the impact of artificial intelligence technology on AR assembly. Lastly, it summarizes the existing challenges and future development trends of AR assembly technology, with the aim of providing a reference for the research and  engineering application of intelligent assembly of complex products in aerospace industry.