The present invention relates to a water supply method for water culture of a large quantity (large amount) of crops disposed in multiple layers in a vertical direction in a greenhouse. Water from an upper water reservoir (tank) arranged as a first layer in the greenhouse firstly flows down and is supplied, via a supply pipe, to a water supply container arranged as a second layer in a horizontal direction below the water reservoir. When the firstly flowed down water reaches a predetermined water level within the water supply container, the water secondly flows down and is supplied to a culturing container arranged as a third layer in a horizontal direction below the water supply container, via a plurality of water outlets arranged at the same height. When the secondly flowed down water reaches a predetermined water level within the culturing container, the water thirdly flows down and is drained to a water drain container via water outlets. The thirdly flowed down water fourthly flows down into a lower water reservoir arranged below the water drain container, via water outlets arranged identically to those of the culturing container, such that the fourthly flowed down water is collected in the lower water reservoir is supplied to the upper water reservoir (tank) by means of an automatic pump. An automatic water supply system repeats the above-described processes to reuse the drained water.본 발명은 온실내 다단수경재배 용수공급 시스템에 관한 것으로서상부에 설치된 자동 수위조절용 저수조(10):저수조 하부에 종단 방향으로 설치된 용수로(20):용수로 하부에 횡단으로 나열하여 설치된 재배용기(30):재배용기 하부에 배수의 집수를 위한 배수로(30a)를 종단 방향으로 설치하고 그리고, 배수로 하단에 자동수위조절용 집 수조(40)를 설치하여, 용수를 상부저수조에서 용수로, 용수로에서 재배용기, 재배용기에서 배수로, 배수로에서 집수조로 하는 단계적으로 하향 낙수하는 방법으로서 공급하는 것을 특징으로 하는 다단수경재배용수공급시스템.
