Method for increasing hybrid rape planting purity by applying herbicide resistant mutant character

The invention provides a method for increasing hybrid rape planting purity by applying a herbicide resistant mutant character, which belongs to a plant breeding method. A conventional breeding technique is applied to transfer and breed imidazoline ketone herbicide resistance to a cytoplasmic male sterility restorer; a resistance restorer is utilized to selectively breed new combination of hybrid rape; and when the new combination F1 is planted, an imidazoline ketone herbicide is sprayed once at the seedling stage, so that all false hybrids without resistance such as trace pollen selfing plants, foreign pollen pollution plants and all mechanical mixing plants in a sterile line can be killed and removed, thereby greatly increasing the hybrid rape planting purity and maximizing the potential yield increase and the yield level of hybrids.