The invention relates to a breeding method of crops, and particularly to a breeding method of broccolini, belonging to the technical field of plant breeding. The breeding method has the advantages that 1. the male sterility line belongs to cytoplasmic male sterility and maternal inheritance, and is stable in sterility, the sterile plant rate and the sterility are 100 percent, nectary is developed, more nectars grow, stigma is normal, flowering and fruiting characters are good, and a seedling does not yellow under the condition of low temperature and can not deteriorate after multi-generation backcross, transform is easy, growth is vigorous, and combining ability is strong; 2. a transformation early generation sterile line is stronger in growth vigor in comparison with a maintainer line and has the advantage of interspecies cross; 3. a later producing shoot of the transformation early generation sterile line is stronger than that of the maintainer line, and thus the transformation early generation sterile line material is early planted by 5 days in comparison with a backcross male parent; 4. F1 is prepared by using the sterile line, the seed yield is high, the seed producing cost is low and the labor is saved; and 5. a new variety prepared by using the sterile line is strong in disease resistance, and is remarkable in production increasing.