The invention relates to a method for preventing and controlling cotton bollworm pupas by applying a drip irrigation technology. The method comprises the following steps of: laying a drip pipe zone and covering a plastic film on a cotton field, suspending a trap lamp (frequency vibration trap lamp, black-light trap lamp and the like) at the edge of the cotton field or putting a cotton bollworm luring agent trap in the cotton field to monitor the quality of cotton bollworm moths; and predicting the eclosion peak time of cotton bollworm pupas according to a monitoring result, and performing drip irrigation in time before the eclosion peak time of cotton bollworm pupas of different generations to prevent the cotton bollworm pupas from undergoing eclosion until the cotton bollworm pupas are stifled in the soil, and block the propagation way of mating and egg laying of adult cotton bollworms from the source. By adopting the method, a prevention and control measure is simplified, the key problem of difficulty in prevention and control of cotton bollworms is solved, maximum results are achieved with little effort, and meanwhile, a large amount of labor force and manpower is saved, the agricultural production cost is lowered, and the farmland ecological environment is protected. The method is a simple, quick and effective method for preventing and controlling cotton bollworms which damage crops.