In order to study the inverse problem which is from continuous to discrete subject to the continuum structural topology optimization with displacement constraints,this paper presents a new bi-level programming model of topology optimization with the structural weight as the goal.Since the polishing mapping and the filtering mapping in the ICM (independent-continuous-mapping) method have the unity of opposites,the topology optimization model established by the traditional ICM method is regarded as the lower programming,in which the displacement constraints explicit formula is deduced by the unit virtual load method while the filtering functions of the elemental weights and stiffness approach the Hurdle function.