The invention discloses an Internet-of-Things water-saving irrigation system. The system comprises a water storage chamber, wherein one side face of the water storage chamber is fixedly communicated with a first conduit, the other end of the first conduit is fixedly communicated with the output end of a water pump, the input end of the water pump is fixedly communicated with one end of a second conduit, the other end of the second conduit is fixedly communicated with a reservoir, the top of the water storage chamber is fixedly connected with a device box, and a central processor, a Zigbee terminal, a humidity setting module and a main power source are arranged in the device box. Through the system, the soil moisture content of farmland can be effectively detected, compared and analyzed, water supply can be conducted according to agricultural needs, manual irrigation is effectively avoided, irrigation efficiency is high, irrigation precision is high, water flow can be effectively controlled, time and labor are saved, the defects existing in the prior art can be overcome to a great degree, the water saving effect is better, the intelligent degree is higher, and serious waste of water resources is effectively avoided.