Abandoned pile foundation is constantly encountered during ground engineering construction; these old piles must be removed to insure successful construction of ground engineering. The paper introduced the mechanism and the method of abandoned pile removing, and discussed the technology, equipment, construction effect and some relevant construction problems. Casing drilling in abandoned pile removing has advantages of simple process, convenient operation, high efficiency and good construction effect with low cost, which could be widely applied in abandoned pile removing within φ1000mm.