Abstract: The Xinjiang Academy, one of Jiangxi Province’s four renowned classic academies during Qing dynasty, served as a pivotal center for the revival of Cheng-Zhu Neo-Confucianism in the late Qing era, exemplifying the garden design principles of Jiangxi academies. However, existing restoration efforts remain incomplete due to limitations in historical records and methodologies. This paper systematically integrates archival materials, visual data, extant architectural remains, and oral histories, employing a multi-evidence verification approach to reconstruct the academy’s garden layout during the Tongzhi period. It clarifies the site’s spatial scale and corrects prior conjectures about its boundaries, achieving an accurate planar restoration. On this basis, it elucidates the garden’s underlying rational design principles, including its harmonization of mountains and rivers in site selection, ritualistic moderation in spatial organization, contemplation of life’s vitality in aesthetic expression, and the moral-didactic role of literature in philosophical framing.