Titanium diboride (TiB2) materials have garnered significant attention due to their remarkable comprehensive properties. They offer potential applications in high-temperature structural materials, cutting tools, armor, electrodes for metal smelting, and wear-resistant parts. However, due to the low self-diffusion coefficient, the TiB2 exhibits poor sinterability, excessive grain growth at elevated temperatures, and inadequate oxidation resistance, limiting its wide application. Therefore, many research works are devoted to processing TiB2 at a lower sintering temperature and improving the properties through various sintering additives and more advanced techniques. This article comprehensively reviews the multiple synthesis methods and sintering technologies of TiB2, and at the same time, critically discusses the impacts of sintering additives and reinforcing agents on densification, microstructure, and various properties, including those at high temperatures, and finally predicts the future development of TiB2 composite materials.