Prevention and control of soil and water loss at slope farmland in South China is urgent and serious.Due to natural conditions, economic conditions, or farming culture in South China, the existing measures of soil and water conservation can’t meet the actual requirements of slope farmland in South China. On the basis of years of experience in soil and water conservation as well as related experiments, we discuss the process and regulation of soil and water loss on slope farmland in South China so as to provide scientific foundation for control on slope farmland. Results show that soil and water loss is a result of the combined action of internal and external factors, and rill erosion on the slope is the most obvious sign of intensive soil and water loss. In the current background of vigorously promoting construction of ecological civilization and construction of Yangtze River Economic Zone, in association with the characteristics of the South China, we take rill erosion elimination as the objective and standard of controlling of soil and water loss of slope farmland. Furthermore, we present the principle of “water discharge and soil conservation” for soil erosion prevention and control on slope farmland, and propose the control measures with “slope runoff regulation” as the core measure, and put forward a new type of drainage ditch and a technique of “conserving soil and increasing fertility” in the aim of improving the regulation of soil and water loss at slope farmland.