The invention discloses an identification method for the clubroot resistance of alpine radish at the seedling stage. The identification method is characterized by comprising the following steps: S1, sieving soil of cultivated land, adding with a fertilizer and plant ash, mixing sterile soil with an organic fertilizer and calcium superphosphate, in addition, adding with plant ash, and preparing culture soil; S2, taking a hole tray as a culture device, adding the culture soil obtained in S1 into the hole tray, and sowing the seeds with the variety to be identified in the hole tray; S3, grinding fungus roots containing plasmodiophoromycetes, filtering the grinded fungus roots by adopting gauze, preparing a pathogenic spore solution, carrying out counting by adopting a blood counting chamber, preparing the spore solution into inoculating bacteria liquid with the concentration being 1x10<7> spores/ml for later use; S4, adding the culture soil into the hole tray for later use; and S5, completely watering the culture soil in the hole tray, when the water settles and the soil is slightly dry and is suitable for sowing, carrying out dibble seeding and earthing at the central point of each hole, establishing a small shed, carrying out normal field management, and investigating the morbidity at the 7th week after inoculation. According to the identification method provided by the invention, through the root irrigation identification method, the clubroot resistance of relevant experimental population can be improved, and thus the method has great values for the disease-resisting breeding practice and theoretical research.