Catalysts play a vital role in the chemistry realm and contribute a lot to the rapid development of the industrial economy. However, traditionally supported catalysts still face severe challenges in practical applications, such as active nanoparticles being prone to migration and aggregation, poor stability, and easy poisoning and inacti-vation. With the introduction of the concept of 'confined catalysis', the use of encapsulation technology to encapsulate active nanoparticles on a carrier has become an effective strategy for designing novel and efficient catalysts. Due to the spatial confinement effect and the electronic confinement impact of the confined catalyst, the active nanoparticles are not only stabilized, but the active species' redox characteristics are also modified, thereby enhancing the overall performance of the catalyst. Therefore, researchers have developed many encapsulation techniques to improve catalyst activity, stability, and selectivity. The synthetic methods for encapsulating active particles will be the starting point in this research, and we will expound on them inde-pendently with alternative catalyst architectures. The implications of confinement catalysts on catalyst perfor-mance will be examined, including catalytic activity, selectivity, stability, and resistance to poisoning. Finally, a brief review of encapsulated catalysis in applying environmental catalysis, such as selective catalytic reduction for NOx removal, the degradation of VOCs, and advanced oxidation processes (AOPs) for environmental reme-diation, and its prospects and perspective are presented. We hope that this review will help reader better un-derstand the influence of confinement effect on catalytic performance and provide some reference for the design of efficient catalysts.