Abstract: As an emerging environmental contaminant, microplastics are widely distributed in aquatic environments. With the characteristics of small particle size, high recalcitrance to degradation, and strong adsorption capacity for co-occurring pollutants, they pose severe potential threats to ecosystems and human health. Conventional water treatment technologies exhibit limited removal efficiency for microplastics, creating an urgent need to develop green and efficient advanced treatment technologies. Photocatalytic technology has attracted extensive attention in recent years: it can generate reactive oxygen species (ROS) under mild conditions to drive the oxidative chain scission and mineralization of microplastics, and realize the resource valorization of microplastics through the photoreforming pathway. This paper systematically reviews the sources, pollution characteristics, and environmental and health risks of microplastics in water environments, clarifies the core reaction mechanism of photocatalytic conversion of microplastics, and focuses on summarizing the research progress and modification strategies of mainstream photocatalytic material systems including TiO2-based, ZnO-based, graphitic carbon nitride (g-C3N4)-based, bismuth-based materials and metal-organic frameworks (MOFs). Meanwhile, it analyzes in depth the existing bottleneck issues in this field, such as low catalytic conversion efficiency, poor adaptability in real water matrices, and unclear ecological risks of degradation products, and prospects the future research directions, with the aim of providing systematic theoretical references and technical support for the research, development and engineering application of photocatalytic remediation technologies for microplastics in aquatic environments.