Currently, building a unified national market has become a key strategic task for promoting high-quality development and facilitating the smooth circulation of both domestic and international cycles. Against this backdrop, the Western Land-Sea New Channel—serving as a vital strategic corridor linking China’s western hinterland with ASEAN and global markets—has been entrusted with significant missions to support the construction of a unified national market, optimize the country’s spatial layout, and promote regional coordinated development. However, existing research has largely failed to examine the channel within the institutional reform framework of the unified national market, particularly overlooking its deeper roles in breaking down administrative barriers, harmonizing market rules, and reducing institutional transaction costs. This study employs a combination of literature analysis and policy text interpretation to systematically elaborate on the multiple values of the corridor in addressing regional imbalances between eastern and western China, linking domestic and international dual circulation, empowering industrial coordination and upgrading, and innovating cross-regional governance models. It further examines four key practical obstacles: insufficient “hard connectivity” in infrastructure, fragmented factor markets, homogenized industrial competition, and lagging alignment with international cooperation rules. Based on this analysis, the study proposes systematic breakthrough pathways, including building an efficient and intelligent interconnected infrastructure network, deepening market-oriented reforms in land, capital, and data, promoting industrial coordination and upgrading based on comparative advantages, and advancing unified market rules and innovative governance mechanisms. The research finds that only by synergistically advancing both “hard” and “soft” connectivity can the corridor evolve from a logistics corridor into a hub for factor allocation and a platform for institutional integration, thereby fostering a new pattern of high-quality development characterized by coordinated land-sea strategies and mutual support between east and west, and injecting sustained and robust momentum into the construction of a unified national market.