Refrigeration control system of screw refrigerating unit

The utility model provides a refrigeration control system of a screw refrigerating unit. The refrigeration control system comprises a temperature detection device, a PLC (Programmable Logic Controller), a screw compressor, a condenser and an evaporator, the screw compressor is communicated with the condenser through a first pipeline, the condenser is communicated with the evaporator through a second pipeline, and the evaporator is communicated with an air inlet of the screw compressor through a third pipeline. The temperature detection device is in signal connection with the PLC, and the temperature detection device is used for detecting the temperature of a motor of the screw compressor. The condenser refrigerates a compressor motor corresponding to the screw compressor through an auxiliary cooling pipeline and/or a main cooling pipeline. And the PLC controls the on-off of the auxiliary cooling pipeline and the main cooling pipeline according to the temperature of the motor so as to realize refrigeration con