In order to solve the problem of the symbiosis of rice, fish and ducks, a technical solution for polyculture of fish and ducks under rice planting was proposed and implemented in Lukou Town, Changsha County, Hunan Province from 2019 to 2020. Through two years of observation, it is found that the“rice-fish-duck” symbiosis model ensured the growth of rice, while also maintained the underwater living environment of fish and the field and surface activity space of ducks. Through the activities and predation of duck and fish, it could effectively prevent and control the occurrence of diseases, pests and weeds in field, and reduce the application of herbicides. At the same time, the manure of fish and ducks could be directly return to the field and reduce the application of fertilizers, which plays an important role in increasing soil nutrient content and reducing farmland pollution. The deep water area in the rice field had the function of storing water and alleviating the shortage of irrigation water. The“rice-fish-duck” symbiosis model has obvious economic, ecological and social benefits.