The invention discloses a spraying device of an aeroponic culture nutrient solution conveying system. The device comprises a fixed bucket, a motor and a spraying pipe; a main fixed bucket body is a hollow shell body, fixed plugging connection holes are uniformly and densely distributed in the hollow shell body, and root hairs of plants extend into the fixed bucket; the motor is fixed to an upper cover of the fixed bucket, and during operation, the motor swings back and forth to drive the spraying pipe to rotate back and forth; a nutrient solution conveying pipe joint is formed in the sprayingpipe and used for spraying a conveyed nutrient solution out through a spraying port. A stepping motor is preferably selected as the motor, during operation, the motor is connected with the spraying pipe and drives the spraying pipe to swing back and forth, and the swing angle is between plus or minus 90 degrees and 180 degrees. The problem is solved that according to an existing aeroponic culturetechnology, the nutrient solution cannot be uniformly sprayed to the root hairs of the plants.