Abstract: With advantages such as small footprint, low power consumption, reconfigurability and low cost, chip-integrated coherent light sources have become a highly promising scheme, applied in optical computing, autonomous driving, high-speed optical interconnection, 5G/6G communications, etc. Combining on-chip integration and cavity enhancement effects, microcavity-based integrated coherent light sources significantly improve the intracavity light power as well as reducing the pump threshold. This paper introduces in detail the principle and research progress of four kinds of microcavity integrated coherent light sources: Kerr frequency combs, microcavity stimulated Raman lasers, quadratic combs and microcavity-enhanced electro-optical combs. The four key parameters of spectrum width, noise, efficiency and power are analyzed one by one, and the research progresses of microcavity-based integrated coherent light sources in communication applications are introduced. At last their future development trends are prospected.