Provided are a rape green revolution gene bgr and a use thereof. The gene bgr can significantly reduce the height of rape plants, achieve thick and strong stems, lodging resistance, a reduced branching angle, and a compact plant type, and can effectively increase the harvest index. The gene has remarkable heterosis, heterozygous bgr can enable tetraploid rape (Brassica napus and Brassica juncea) to have more ideal plant type characteristics, the plant height is 120-160 cm, the plant type is compact, the branching angle is small (less than 30°), the first branching position is lowered, the harvest index is increased by about 29.03%, the gene is suitable for close planting, and the yield is greatly increased by 11-27%. The oil content of hybrid Brassica napus having bgr is greatly increased and can reach 51.7-54.86%, and compared with the oil contents of common high-oil-content rape varieties, the oil content is increased by 9.14-19.26%. A valuable genetic resource is provided for rape breeding, and an effective means is provided for creation of new rape germplasm.