###### Abstract  
The pressurized capsule structure provides the pressure environment for astronauts or payloads in space, which is thus considered as the most crucial structural component for manned spacecraft. The manned deep space exploration mission (MDSEM) brings new challenges to the pressurized capsule structure: extremely low structural weight, long service life, reusability and adaptability to the harsh deep space environment. The conventional welded panel pressurized capsule structure (WPPCS) is not able to meet these new requirements. To address the above challenges, this paper comprehensively expounds why the current WPPCS cannot meet the requirements of MDSEMs based on the analysis of the vibration environment and structural characteristics of the pressurized capsule structure. Furthermore, a new type of integrated panel pressurized capsule structure (IPPCS) is proposed, showing the lightweight advantage compared with WPPCS. Finally, the technical details and research results of the strength criterion, design method, material upgrading and structural integrity manufacturing process of the IPPCS are fully introduced. The conclusions drawn in this paper will provide useful and meaningful references for the future development of large-size, lightweight pressurized capsule structures. m m  
the lightweight technology. Pressurized capsule structures have distinct characteristics compared to general spacecraft structures and impose higher requirements in terms of functional performance, mechanical performance, sealing requirements, safety reliability, fatigue life and fracture control. These structures are subject to multiple constraints and exhibit complex mechanical responses. Therefore, conducting lightweight design for pressurized capsule structures under these multiple constraint conditions presents significant challenges. Conducting targeted research on all aspects of pressurized capsule structure design and thoroughly exploring each element to reduce structural weight is an important approach for improving the lightweight level of these structures. Currently, a widely used structural component for manned pressurized capsule structures in space station missions is the welded panel pressurized capsule structure [2; 3; 4; 5]. In comparison to near-Earth spacecraft, manned deep space exploration spacecraft have higher requirements for structural weight, service life, reusability and adaptability to space environments [6; 7]. The inherent limitations of WPPCS hinder its direct application in manned deep space exploration missions. Based on current trends in structural design development, it is understood that higher structural integration leads to a lower number of components and structural connectors, thus guiding efforts toward reducing structural weight. Expanding upon the foundation of WPPCS, an IPPCS has gradually become the prevailing structural component for manned deep space exploration compartments, driven by the concept of enhancing structural integration. To comprehensively summarize the development trends of panel pressurized capsule structures, research and analysis will be conducted from two perspectives in this paper: the advancement of pressurized capsule structure technology and the requirements of the MDSEM. This approach will not only capture the patterns of technological upgrades in pressurized capsule structures but also provide valuable insights for forecasting future development trends. The remainder of this paper is organized as follows. Firstly, the function, type, and flight environment of the pressurized capsule structure are analyzed, the characteristics of the design load conditions are summarized, and the design constraint system of the pressurized capsule structure is constructed. Then, the higher requirements and new demands of the MDSEM for the pressurized capsule structure are analyzed, and the development direction of the pressurized capsule structure technology is defined.