The invention relates to the field of drying, in particular to a multifunctional humidity control drying plant and a humidity control manner. The multifunctional humidity control drying plant comprises a curing barn, and further comprises an air inlet door, a humidity discharging opening, a compressor, an evaporator, a condenser, an auxiliary condenser, a crossed flow heat exchanger, an air returning opening, an air outlet and a control module, and the auxiliary condenser is connected with the air returning opening; the condenser is connected with the auxiliary condenser so as to be connectedwith an internal circulation draught fan, the air outlet is connected with the curing barn, the crossed flow heat exchanger is connected with the air returning opening so as to be connected with the air inlet door and the humidity discharging opening, and the evaporator is connected with the humidity discharging opening so as to be connected with an external circulation draught fan; and the compressor is connected with the evaporator, the condenser and the auxiliary condenser, and the control module is electrically connected with the compressor, the internal circulation draught fan, the external circulation draught fan, the air inlet door, the humidity discharging opening and the auxiliary condenser. By means of the multifunctional humidity control drying plant, multiple humidity control manners can be achieved in the drying process, free switching can be achieved, and the aims of improving the drying efficiency and enlarging the applicability are achieved.