Small-scale farmer is defined by the domestic and foreign experts and scholars. They point out that since the fragmentation of production and the diseconomy of scale in small-scale farmer is inconsistent with the characteristics of scale and technology of modern agricultural production, it is necessary to eliminate the adverse effects of existing mode in order to provide theoretical references. Citrus industry in Shimen County, Hunan Province, China is introduced from the aspects of natural geographical condition and socio-economic benefit. Impact of small-scale production mode on citrus production in Shimen Country is discussed. Firstly, blindness of small-scale production is the main reason leading to overproduction of citrus. Secondly, small-scale production mode has limitation on the acceptance of new technologies, restricts the operation of geographical trademark, and constraints the enthusiasm of enterprises in entering the agricultural filed. Finally, suggestions are put forward, such as encouraging the circulation of rural land, improving the organization degree of farmers, changing the work function of grass-roots government and perfecting the agricultural financial credit system.