The invention discloses a method for cultivating an aneuploid perennial forage grass variety by using a corn heterologous polyploidy and belongs to the field of corn distant hybridization. According to the method, MTF-1 (Tripsazea creammaize T.2n=76) cultivated by Sichuan Agricultural University is used as a female parent and teosinte is used as a male parent to be hybridized; a filial generation is selected from perennials, a wintering habit, a tiller number, a chromosome number and chromosome constitution to select the perennial heterologous aneuploid forage grass variety. According to the method, firstly, a heterologous aneuploid is used as the forage grass variety to be applied so as to creatively expand an application range of corn affinis species and explore a novel way for utilizing corn affinis specie materials; secondly, a material cultivated by the method is used as a bridge material and has a very great application value; furthermore, a vegetative propagation manner can be used for fixing a hybrid vigor and the variety is perennial, so that the production cost is very low, the yield and the nutritive value are high, and the economic benefit is great.