Combined with the engineering case of the retaining structure design of a super high-rise building in Suzhou, the reinforcement steel was optimized; comparison was made on the strength, stiffness and economic of surrounding non-uniform reinforcement and uniform reinforcement; and study was made on the stress deformation characteristics of foundation pit under the condition of retaining piles with different length. The results show that there is little change in mechanical behavior when non-uniform reinforcement steel and retaining pile with different length are adopted, but low project cost, short construction period and the best economic and social benefits can be achieved.