The invention discloses a combined cold and power dispatching system comprising a gas combined cycle unit and a dispatching method thereof. The system comprises a gas combined cycle unit, a centralized heat absorption refrigerator, an air conditioner, an electric energy meter, a refrigerating fan coil, a cold-consumption gauge, a second remote centralized controller and a dispatching control device, wherein the second remote centralized controller is used for collecting the power consumption data detected by the electric energy meter and the refrigerating cold-consumption data detected by the cold-consumption gauge, and the dispatching control device is used for controlling the running of the gas combined cycle unit, the air conditioner and the refrigerating fan coil through a first and second remote centralized controllers. A pipeline distance from a user to a cold source is collected and the pipeline distance is utilized to reasonably dispatch the gas combined cycle unit, so that an error between a load value practically required by the system and an electric load predicted value is greatly reduced, the running and the planning of the system are boosted and the dispatching difficulty is reduced.