The invention discloses an anti-overpressure compound fertilizer granulation assembly system which comprises a granulator and a drier connected with the granulator. The system is characterized in that the granulator comprises a rotating drum, wherein the top of the rotating drum is provided with a feed port, the middle of the rotating drum is provided with a worm transmission part, the position with the same center of circle as the worm transmission part in the rotating drum is provided with a rotary sprayer, and the rotating drum and the rotary sprayer are driven to rotate by the same power source. The system has the advantages of ingenious and reasonable design and high systematicness; by arranging the multistage equipment, the system can effectively implement the functions of granulating, drying screening and assembling the compound fertilizer, has high degree of automation and superior performance; and compared with the existing split equipment, the efficiency is enhanced by more than 40%, and the economic benefit is enhanced by more than 30%.