This　paper　investigates　the　effectiveness　of　applying　continuous　high-compression　pressure　on　the　initial　setting　of　fresh　concrete　to　produce　hardened　concrete　materials　with　excellent　mechanical　properties.　A　novel　experimental　apparatus　was　self-designed　and　used　for　the　pre-setting　pressure　application.　The　utilization　of　the　completely　decomposed　granite　(CDG)　soil　as　an　alternative　aggregate　in　concrete　production　was　also　explored.　A　total　of　twenty-eight　specimens　were　fabricated　using　two　types　of　fine　aggregates,　six　mix　ratios,　two　initial　pressure　values,　and　two　distinct　durations　of　the　initial　pressure　application.　The　density　and　uniaxial　compressive　strength　(UCS)　of　the　specimens　were　examined　to　evaluate　their　mechanical　qualities,　while　micro-CT　tests　with　image　analysis　were　used　to　quantify　their　porosity.　The　results　indicated　that　the　10　MPa　initial　pre-setting　pressurization　can　effectively　eliminate　the　excess　air　and　voids　within　the　fresh　concrete,　therefore　enhancing　the　mechanical　properties　of　the　hardened　concrete　specimens　of　various　types.　Compared　with　non-pressurized　specimens,　the　porosity　values　of　pressurized　specimens　were　reduced　by　73.11%　to　86.53%,　the　density　values　were　increased　by　1.43%　to　8.31%,　and　the　UCS　values　were　increased　by　8.42%　to　187.43%.　These　findings　provide　a　reference　for　using　a　continuous　high　pre-setting　compression　pressure　and　using　CDG　soil　as　an　aggregate　in　the　fabrication　of　concrete　materials　with　improved　mechanical　performance.