The　performance　of　the　recycled　cement　concrete　is　influenced　by　a　great　deal　of　factors,　such　as　compressive　strength　of　recycled　aggregates,　water　content　and　replacement　ratio.　This　test　uses　the　Auto　Pore　IV　mercury　porosimeter　to　analyze　the　microstructure　and　performance　of　recycled　concrete　with　different　mixing　proportion　of　recycled　aggregate.　Studies　have　shown　that　if　the　mixing　proportion　of　the　recycled　aggregate　is　less　than　60%,　then　some　properties,　such　as　slump　of　the　recycled　concrete　and　compression　strength,　will　drop　to　some　extent.　Adjusting　mixing　proportion　can　meet　the　specification　requirement.