Abstract: Hainan will officially launch the closure of the island-wide FTTP on 18 December 2025, and the proportion of ‘zero-tariff’ commodities will jump from 21% to 74%, which will have a strong impact on Hainan's local agricultural products market. To address this challenge, this study constructs a partial equilibrium model to quantitatively simulate the impact of customs closure on the local grain and fruit industries. The results show that after the closure, cereal market prices are expected to fall by 48.2%, local supply will decrease by 9.6%, and imports will surge by 5 times; fruit market prices will decrease by 11.2%, local supply will decrease by 3.4%, and imports will increase by 68.2%, suggesting that the closure of the border will form a ‘double squeeze’ on local agricultural products through price transmission: on the one hand, it will inhibit local production, and on the other hand, it will intensify import substitution. In response to this impact, this study proposes differentiated industrial support strategies, including the implementation of a target price insurance system for the food industry to protect the bottom line of regional food security, the fruit industry to strengthen branding and industry chain extension to enhance market competitiveness, and suggests the establishment of an industry chain-wide big data monitoring platform to achieve precise risk prevention and control, to provide a theoretical basis and practical references for the agricultural response to the challenges of the closure of Hainan.

Key words: Hainan free trade port, closing operations, industrial resilience, hedonic modelling, tropical agriculture, value chain reconstruction