Abstract: As the global population grows and the economy develops rapidly, the energy crisis and global warming triggered by the overconsumption of non-renewable resources, are becoming increasingly serious and poses a major challenge to the sustainable development of human society. Therefore, the development of energy efficient and sustainable technologies is of great significance. Radiative cooling (RC) and phase change materials (PCM) thermoregulation are highly favoured. However, there are obvious limitations in the thermal management capability of a single passive cooling technology in practical applications. In recent years, synergising the advantages of both through the coupling technology provides an effective way for thermal management and energy saving, and thus has received widespread attention. In this paper, we firstly explain the cooling principle of the RC-PCM coupling, then summarize its preparation methods and analyse the advantages and disadvantages from the perspective of how to inhibit the leakage of phase change materials, and discuss the synergistic effect of RC-PCM coupling in both thermology and optics in depth. In addition, the applications of this coupling material and technology in the fields of building energy saving, personal thermal management and heat dissipation of electronic devices are also reviewed in detail. Although the coupling of RC-PCM has demonstrated significant thermal management advantages, it still faces the problems of long-term material stability, synergistic optimisation of multiple properties and manufacturing cost. Finally, it was pointed out that future research should be devoted to developing multifunctional materials, designing multi-scale structures, advancing green, low-cost scalable preparation technologies and constructing intelligent environment-responsive systems, thereby promoting the practical applications of the coupling technology of RC-PCM in the fields of energy saving and carbon neutrality.