The present invention provides an assembly well irrigation system for environmentally friendly water conservation, comprising: at least one well, its bottom is enclosed and forms a tip whose the top sets a waterproof ring said tip of said well can be cut to make said well form a tubular shape, its top has a connecting element setting a through hole and a connect hole a ventilation tube inserting said connect hole of said well and having a plurality of water guiding holes, the outer wall surface and the bottom of said ventilation tube is covered by an absorbent element in order to make the absorbent element fill the opening which is between said well’s top and said ventilation tube, and a float is located in said ventilation tube a holder connecting with the top of said connect hole a water supply bottle inverted at the holder a fixed tube and a movable tube of the water supply bottle inserted in said well by said connect hole the side of said connecting element having a hook for hanging a planting container when said well is buried in the soil, under the condition that the water level is not higher than the opening of said well, the water will permeate and follow said absorbent element into the soil being outside of said well for irrigation, and the effects of the present invention are described as follows: 1. Because said ventilation tube is inserted in said well, it communicates with the outside of said well so as to let the air pressure can be released by said ventilation tube and make the water smoothly flow into said well when the water flows into said well. 2. By the height of said movable tube which is inserted into said well, the present invention can maintain or control every water level height of said wells based on the communicating pipe principle so as to let every water level height of said wells is equally. 3. A float can insert in said ventilation tube, so it is easier for a user to know the water level height of said well. 4. The present invention
