Promoting farmers' income growth by realizing ecological product value is a vivid interpretation of the concept that 'green mountains and clear waters are as valuable as mountains of gold and silver’.As an important national grain-producing region and an area rich in ecological resources, the Dongting Lake basin plays a significant role in promoting farmers' income growth and achieving common prosperity through ecological product value. According to the characteristics of different categories of ecological products such as material supply, regulating services and cultural services, we sort out their different value transformation scenarios and value realisation forms, and analyse the impact mechanism of ecological product value realisation on farmers' income increase. On the basis of these analyses, the paper utilizes panel data from the Dongting Lake grain-producing region from 2013 to 2022. It refers to the Gross Ecosystem Product (GEP) accounting framework to assess the aggregate ecological product value in the major counties and cities of the region, uses a two-way fixed effects model to examine the impact of ecological product value on farmers' income, and analyses its heterogeneous effects at different income levels. The results indicate that: (1) From 2013 to 2022, the gross ecological product value in the main grain-producing areas of Dongting Lake showed a gradual upward trend, with urban centers such as Wangcheng District and grain-producing counties such as Taoyuan County having higher ecological product values; (2)The realization of ecological product value has a positive effect on the income growth of farmers in the main grain-producing areas of Dongting Lake, with regulatory service-type ecological products having a more significant effect on farmers' income growth; (3)The realization of ecological product value shows certain differential effects on farmers' income structure, with the greatest effect on farmers' operating income compared to other income components. (4) The realization of ecological product value can significantly improve the income level of rural middle- and low-income groups, thereby contributing to narrowing the income gap among farmers. Finally, this paper combines the agricultural ecological resources and ecological product advantages of the grain-producing areas of Dongting Lake to propose policy recommendations from the following aspects: strengthening the material foundation for farmers' income growth, improving the mechanism for realizing the value of ecological products in the regulatory services category, promoting the industrialization and marketization of ecological products, and strengthening the protection of ecological product value-added benefits for rural low- and middle-income groups.