Natural pollination hybridizing method with castration for longan

The invention belongs to the technical field of fruit growing and particularly relates to a natural pollination hybridizing method with castration for longan. The method is characterized by comprising the following steps: (1) selecting a single-variety male parent connected orchard, and top-grafting female parents onto male parent plants while ensuring that the flower insertion positions of the female parents are lower than those of the male parents, or planting female parent plants into large flowerpots and putting the heading female parent plants under the male parent plants; and (2) after the female parent plants (or branches) flower, removing male flowers with tweezers before male flower anther dehiscence at 6:00 to 8:00 every morning, shaking female parent plant branches with force at 9:00 to 10:00 every morning for dispersing anther, and picking all male flowers and buds when female flowers of the female parent plants finish flowering and before the second batch of male flowers flower. According to the invention, the links of collecting male parent anther, collecting pollen, pollinating manually and bagging can be reduced, and the working efficiency and the fruit setting rate can be improved.