Abstract: To investigate the current status, model suitability, and operational effectiveness of rural domestic wastewater treatment in tropical island regions, this study examined 741 rural domestic wastewater treatment facilities across 18 cities and counties in Hainan Province. Through field investigations, literature review, and spatial statistical analysis, a systematic evaluation was conducted on the treatment rate, treatment models, operational issues, and maintenance mechanisms of rural domestic governance. The results indicated that: (1) In terms of governance status, the rural domestic wastewater treatment rate in the 18 cities and counties of Hainan ranged between 63.85% and 100%, with a provincial average of 80.1%, significantly higher than the national average. The distribution of treatment rates did not exhibit significant spatial clustering, though hotspot areas were concentrated in mountainous and humid regions such as Wuzhishan and Baisha, where treatment rates were as high as 100% and 96.01%, respectively. (2) Regarding treatment models, four categories were identified: "connection to municipal networks""treatment with compliance discharge in rural suburban waterfront areas ""centralized resource-oriented treatment", and "decentralized resource-oriented treatment". Among these, decentralized resource-oriented treatment accounted for 62.6% of the surveyed facilities. (3) In terms of facility operation, 48.6% of the facilities faced operational issues, primarily attributed to extreme weather, equipment failure, and treatment process-region mismatch. The mountainous humid region recorded the highest problem rate (64.3%). (4) In terms of maintenance models, a "government-led, multi-stakeholder participation" approach was observed, with local entities demonstrating good adaptability. The study reveals that challenges remain in wastewater collection, model selection, facility quality, and operation and maintenance, necessitating optimized strategies based on spatiotemporal distribution characteristics. The findings offer insights for wastewater governance in Hainan and other comparable tropical regions.