跨域飞行器凭借“一机多能”和大空域、宽速域高效重复飞行的设计定位，在航空航天领域具有划时代意义，正在成为各国科技竞争的焦点之一。由于这一领域高度的前沿性和综合性，目前尚未形成实现大包线跨域飞行的明确技术路线，但是普遍认同变构型是其中的关键技术与必要手段。本文以变构型为主线，从与之相关的飞行器基础构型、变体方式、变体结构优化与热防护四个方面论述了实现跨域飞行的概念性路线，分析了现有研究对跨域飞行器设计提供的技术铺垫和参考价值，并综述了各自的技术进展与挑战。首先，介绍了几种有应用潜力的基础构型，对比了气动性能、容积率等方面的差异；其次，按照机翼和头锥部位变体分类，分析了不同方案的结构设计和气动影响；接着，从提高变体结构变形、承载与防热性能的角度，介绍了三个层次的结构优化技术和被动、主动热防护结构设计；最后，总结了目前跨域飞行器结构与变构型设计工作仍面临的挑战与难题，展望了相关研究在未来的发展方向。

By the virtue of its design orientation of “multi-functionality” and efficient repeated flights in large airspace and wide speed range, the cross-domain vehicle is of epoch-making significance in the field of aerospace and is becoming one of the focuses of technological competition among various countries. Due to the high frontier and comprehensive nature of this field, there is no clear technical route to realize the large envelope cross-domain vehicle, but it is generally agreed that the morphing configura-tion is the key technology and necessary means. In this paper, we discuss the conceptual routes to achieve cross-domain vehicle from four aspects, namely, the basic configuration, the morphing mode, the optimization of the morphing structure, and the thermal protection, with the morphing configuration as the main theme. We analyze the technology pavements and reference values provided by the existing researches on the design of cross-domain vehicle, and summarize the respective technological advances and challenges. Firstly, several basic configurations with application potential are introduced, and the differences in aerodynamic performance and volumetric ratio are compared; Secondly, the structural design and aerodynamic impacts of different schemes are analyzed according to the classification of wings and head-cones; Then, three levels of structural optimization techniques , passive and active thermal protection structural designs are introduced from the perspective of improving the deformation, load-bearing, and thermal protection performance of the morphing structures; Finally, we summarize the challenges and problems that are still facing in the work of cross-domain vehicle structures and morphing configuration design, and look forward to the future development direction of related research.