The invention relates to a soilless cultivation system of capillary hydroponics, comprising a plurality of culturing grooves, a liquid storage tank, a liquid feeding pipe, a water pump, a flowmeter, a timer, a first backflow pipe, a second backflow pipe, a backflow tank, a pressure pump, a water filtering and disinfecting device, and a fertilizer blending tank. The tables for fixing and putting plants in the culturing grooves of the soilless cultivation system of capillary hydroponics are set fixedly, such that there is no damage to the roots of plants because of the liquid level changes of the nutrient solution and no worry about water or power cut because of the 5cm height of the nutrient solution. The invention adopts the root separating method to solve the conflict of oxygen uptake and liquid supplement with low consumption of energy. in addition, The bottom of the culturing groove can be provided with a culturing frame having the function of supporting to completely change the traditional stooping or squatting working way of the workers in the past, which is not only good for easy operation and management, but also for easy cleaning of the residue roots after harvesting. So the labor intensity can be reduced.