设计了一种具有优良综合力学性能的中碳Ｓｉ－Ｍｎ－Ｍｏ系超高强度贝氏体钢。给出了成分－性能关系，测定了ＣＣＴ图，考察了低温回火对性能的影响。组织分析表明，该钢在轧态下是一类以无碳化物的特殊贝氏体－准贝氏体为主的组织，此种组织的获得是设计钢种具有超高强度及良好韧塑性配合的主要成因。 A medium carbon Si-Mn-Mo ultra-high strength bainitic steel with excellent mechanical properties was designed. The composition-property relationship was given and the CCT chart was measured. The effect of low-temperature tempering on the properties was investigated. Tissue analysis shows that the steel is a kind of non-carbide special bainite-quasi-bainite-based microstructure in the as-rolled state. This kind of microstructure is obtained by designing the steel with ultrahigh strength and good toughness and plasticity The main reason.