The invention relates to the technical field of livestock breeding, in particular to a full-automatic feeding system for liquid fodder feeding in a pig farm. The system includes a fodder blending tank, a storage tank, a water storage container, a cleaning water pump, a fodder acquirement water pump, multiple dry fodder towers, a high-pressure draught fan, a plurality of feeding stations, an air pump, a plurality of pneumatic valves and a PLC device. The feeding system for liquid fodder feeding runs in a full-automatic mode without management of staff, as long as there are electric power, waterand dry fodder, liquid fodder feeding can be automatically and accurately completed, not only can it ensured that a water-fodder ratio and the feeding frequency meet the demands of live pigs in different growth periods, but also the operating cost of the pig farm can be greatly reduced, and the feeding efficiency of the liquid fodder is improved.