The construction industry serves as a pillar of China’s national economy and a key driver of regional development, playing a vital role in the global economy. As one of the most representative urban agglomerations, the Guangdong-Hong Kong-Macao Greater Bay Area (GBA), characterized by its unique “one country, two systems, and three jurisdictions” framework, presents significant challenges for in-depth exploration of cross-regional cooperation factors and the analysis of their complex interactions. Given the effectiveness of large language models (LLMs) in general cognition and reasoning, this study develops a cross-regional expert consultation agent grounded in domain knowledge of the construction industry. Using intelligent consultation on influencing factors as a case example, we examine the feasibility and effectiveness of applying AI technologies to analyze the determinants of cross-regional collaboration in the construction sector.