The invention relates to the technical field of crop planting and aquaculture, in particular to a breeding method of crawfish polyculture in a lotus root field. The method comprises the four steps of farmland work of lotus root field construction, selection of cultivation and breeding time, cultivation management of lotus roots and breeding management of crawfish. According to the breeding method, water body space of a lotus root field piece is sufficiently used for culturing crawfish, firstly, aquatic plants and biological baits in the lotus root field can be used as natural feed of the crawfish, the biological weeding effect of the lotus root field is achieved, and the use ratio of the lotus root field is improved; secondly, excrement of the crawfish can further provide organic fertilizer for the lotus root field, virtuous cycle is achieved, and therefore the method has wide application prospects in the technical field of crop planting and aquaculture and is suitable for industrialization large-scale development and usage.