With the increasing complexity of Agri-food supply chains and the growing demand for food safety and transparency, blockchain technology presents a promising solution. However, effectively integrating blockchain into Agri-food supply chain collaboration and determining the most suitable collaborative model remain pressing challenges. This study examined the practical implementation and collaboration model of a blockchain-integrated Agri-food supply chain in China, using DN Rice Smart Farm as a case study. Adopting a qualitative research approach, data were collected through semi-structured interviews with seven respondents, including farm managers and department directors. Thematic analysis was employed to interpret the findings. The results indicated that implementing a blockchain-based collaboration model transformed the traditional Agri-food supply chain, addressing collaboration challenges in an environment of low trust among participants. This case study provides a practical and referable model for applying blockchain technology to enhance collaboration in Agri-food supply chains, particularly within smart farms.