Different planting methods affect the root system and yield of oilseed rape. Direct seeding showed better root traits than assistant transplanting, which was better than direct transplanting. The hybrid variety HZ10 had better root traits, shoot biomass, and seed yield than the conventional variety HS5. Shoot biomass and seed yield were linked to root traits in all planting methods. Varieties with stronger roots can absorb more nutrients and water, leading to higher biomass and seed yield. Root breeding is crucial for improving oilseed rape yield.