The invention provides a method for constructing an artificial ecological island in wetland, which is to stack building waste and river mud or pond sludge into an island body according to the volume ratio of 2 to 3 on the basis of the prior natural island or a hard foundation in the wetland, and level and grind the island body layer by layer during the stacking; the circumference on the top of theisland body is placed by stone and cement mortar, and xerophytes and hygrophytes are planted in the middle on the top of the island body; the stone and the cement mortar are used for placing vertically and horizontally frame bodies on the circumferential island slope of the surface of the island body; waste concrete bodies or gravel is filled into spaces of the frame bodies; slurry is sprayed orpoured on the waste concrete bodies or the gravel, and the thickness of the slurry can cover the gravel or rubble; hygrophytes, emergent aquatic plants and submerged plants are planted on a slurry layer; and larger plants are planted before the waste concrete bodies or the gravel is filled. The method has low cost, is convenient to construct, is favorable for conserving water and soil, reduces thegradation degree of the island body, and makes a wetland ecosystem maintain stable.