The invention belongs to the technical field of 
irrigation, and more particularly relates to a 
fiber-bundle-based water-saving 
irrigation system, wherein 2-5 main pipes are parallel to each other and connected with the side wall of a water tank; two sides of each main 
pipe are respectively provided with 3-30 L-shaped communicating pipes; the horizontal end of each communicating 
pipe is connected with each main 
pipe through a three-way joint, and the vertical end of each communicating pipe is communicated with the bottom of a 
crop container of an 
irrigation unit; and in the irrigation unit, a bracket is arranged on the ground of a 
greenhouse, the 
crop container is arranged on the bracket, 
fiber bundles in the 
crop containers are inserted into the communicating pipes, 
fiber bundle heads of the fiber bundles in the crop container are downwards inserted into the vertical pipes of the L-shaped communication pipes, cylindrical 
fiber bundle bodies of the fiber bundles are vertically buried into cultivation soil in the crop container, the upper ends of the fiber bundles extend to 1 / 3-1 / 2 height of the cultivation soil in the crop container, and crops are planted in the cultivation soil in the crop container. The fiber-bundle-based water-saving irrigation 
system is free from manual operation and is capable of automatically pumping for irrigating under the condition that a 
water source is sufficient and is suitable for irrigating 
greenhouse pot culture crops, such as 
bonsai, flowers and plants and the like.