The invention discloses a stem-segment <60>Co-gamma ray radiation mutation breeding method for sweet potato. The method provided by the invention comprises the steps of seedling collection, mutation treatment, transplanting and management after transplanting, and continuous cutting propagation and artificial selection of mutant individuals. According to the invention, a treated material is a stemsegment (comprising terminal buds and a great amount of lateral buds), so large quantities of materials can be treated by one time, and the breeding period is effectively shortened; through a vegetative propagation manner of continuous cutting, generation of a chimera is overcome, and stable and uniform variant plants are obtained; meanwhile, by adoption of <60>Co-gamma ray radiation for mutationof the stem segment of the sweet potato, rich genetic variation can be created; the genetic basis of the sweet potato is broadened; a simple, convenient and highly-efficient method is provided for breeding of new varieties of the sweet potato; and the genetic basis of germplasm resources of the sweet potato is broadened.