TiC ceramics have the characteristics of high melting point and density, and titanium reserves on earth are extremely large; therefore, TiC ceramics are considered ultra-high temperature materials with great research value. However, the development of TiC-based ultra-high temperature composites has been seriously hindered by their poor mechanical properties. At present, improvement of the mechanical properties of TiC is mainly accomplished by adding a second phase. In this paper, the research status of modified elements-, nitrides-, and metal-reinforced TiC matrix composites is presented. The microstructure, phase composition, and toughening mechanism of TiC matrix composites reinforced by a second phase are described. The influence of the reaction products on the matrix during the toughening process is also discussed.