The invention discloses an adjustable storage bin special for compound fertilizer production. The adjustable storage bin special for compound fertilizer production comprises a main body, a vibration exciter, two opening degree adjusting mechanisms symmetrically arranged along the main body, an air cylinder and a displacement sensor. During operation, the air cylinder acts to push a vertical plate through a connecting rod to rotate around a rotating shaft, two gears are mutually engaged to maintain motion stability, and the displacement sensor is used for monitoring the stroke of the air cylinder in real time, so that the distance between two plugging plates is subjected to precision control and the opening degree is controlled; then the vibrator exciter works, so that composite fertilizer raw materials in the main body fall down successfully. The device is simple in structure, the composite fertilizer raw materials are discharged smoothly, and the opening degree can be adjusted, so that the requirements of different working conditions are met.