The invention relates to a method for breeding cucumis allotriploid cucumbers, belonging to the field of biotechnological breeding. The method is special for chromosome engineering and ploidy breeding of cucumbers. Cucumis diploid new species are positively and negatively hybridized with diploid cucumbers; and the seeds harvested from the hybridized fruit are the seeds of the allotriploid cucumbers. The seedling allotriploid cucumbers have strong growth potential and excellent economic characteristic, and can serve as low-temperature-resistant, weak-light-resistant and Meloidogyne incognita Chitwood-resistant processing type greenhouse culture cucumber new species to be popularized and applied. The seedling allotriploid cucumbers provide precious materials for researching scientific problems such as cucumber cotyledon genetic development law, fruit development, parthenocarpy mechanism, heterosis mechanism and the like, facilitates utilization of the allotriploid cucumbers, and contributes to transducing wild type excellent genes to culture the cucumber new species.