The utility model relates to a prefabricated cabin air conditioner system, in particular to a lower air feeding air conditioner system of a prefabricated cabin of an intelligent substation. The system is structurally characterized by comprising a machine room air conditioner and a low-temperature air static pressure box, the low-temperature air static pressure box is an empty space below an elevated floor, an air outlet of the machine room air conditioner is downwards communicated with the low-temperature air static pressure box, an air feeding inlet is formed in the lower portion of each cabinet, and an air returning opening of the machine room air conditioner is located above an air conditioner and communicated with air openings in the upper portions of the cabinets with an upper space in the prefabricated cabin as a communicating space. The system has the advantages that the temperature gradient in the prefabricated cabin can be gradually increased from bottom to top, the flowing direction of gas is consistent with air characteristics, the cooling efficiency of air is effectively improved, and therefore refrigerating efficiency is high, energy consumption is low, and investment cost is reduced.