In the proposed topology optimization method, the whole optimization process is divided into two phases. Firstly，an optimization model dealing with varying displacement limits and design space adjustment approaches， after the combination of structural discrete topology variable condition and the original objective， are built. Secondly，incorporating smooth optimization algorithm，a procedure is proposed to solve the optimization problem of the first optimization adjustment phase. This design space adjustment capability is automatic when the design domain needs expansion or reduction, and it will not affect the property of mathematical programming method convergences. The structural topology approaches to the vicinity of the optimum topology when the first optimization adjustment phase ends. Then, a heuristic algorithm is given to make the topology of the design structure be of solid/empty property and the optimum topology is obtained during the second optimization adjustment phase. The simulation shows that the topologies obtained by the proposed method are of very good 0-1 distribution property, the proposed method is robust and efficient.