Abstract: Direct-drive inertial confinement fusion offers high laser-target coupling efficiency and is a promising route toward fusion energy. However, when intense laser beams propagate through coronal plasma and overlap near the target, different types of laser-plasma instabilities can be excited. These processes lead to laser scattering and energy transfer, causing coupling loss, drive asymmetry and hot-electron preheating, thereby degrading target compression and fusion gain. This paper reviews recent experimental, theoretical and simulation studies of laser-plasma instabilities in direct drive. It summarizes the main risks, outlines multiscale numerical methods and experimental diagnostics. The mitigation approaches, such as material doping, beam smoothing, dynamic zooming, wavelength detuning, broadband lasers and higher-frequency lasers, are discussed.