The invention provides an out-of-season breeding method for gladiolus hybridus hort seed bulbs and belongs to the technical field of flower planting. To solve the problems of long storage period and great nutrient loss of the gladiolus hybridus hort seed bulbs in the conventional summer flowering system, the invention provides the out-of-season breeding method for the gladiolus hybridus hort seed bulbs, which comprises the following steps of: (1) selecting the seed bulbs; (2) using a bactericide and an insecticide to sterilize the seed bulbs after immersion; (3) planting the seed bulbs during the period from September to November; (4) performing managements such as watering, weeding and the like on the seed bulbs after planting; and (5) collecting the planted seed bulbs in six months, wherein dormancy of the seed bulbs can be broken and the seed bulbs can be planted as soon as the seed bulbs are stored for 60 days at the storage room temperature of between 2 and 5 DEG C. The gladiolus hybridus hort seed bulbs bred by using the method has high quality and short storage period, so the aim of flowering in winter is fulfilled, and the production gain is maximized.