The　compressive　strength　of　concrete　is　not　the　same　in　high　temperature　humid　environments　and　normal　temperature　dry　environments.　In　this　study,　quasi-static　uniaxial　compression　experiments　of　concrete　with　different　temperatures　and　water　contents　were　carried　out　to　investigate　the　variation　pattern　of　the　compressive　strength　of　concrete　under　combined　heat　and　moisture　conditions.　The　results　showed　that　the　temperature　softening　effect　and　water　softening　effect　of　the　compressive　strength　of　concrete　were　coupled　with　each　other.　The　compressive　strength　exhibited　a　variation　trend　from　increase　to　decrease　with　the　increase　in　both　temperature　and　water　content,　and　the　relations　among　the　heat–moisture　coupling　factor,　temperature,　and　relative　saturation　ratio　were　obtained.　The　water　absorption　of　concrete　after　immersion　had　a　more　significant　effect　on　the　compressive　strength　than　the　free　water　content　stored　inside　the　specimen　before　immersion.　The　“pseudo-temperature　strengthening　effect”　distinguished　the　thermodynamic　response　of　immersed　concrete　from　that　of　dry　concrete,　and　the　functional　relationships　among　the　heat–moisture　coupling　factor,　temperature,　and　relative　water　absorption　ratio　were　established.　The　evolutionary　mechanism　of　the　competition　between　the　microcrack　expansion　and　healing　of　concrete　under　combined　heat　and　moisture　conditions　was　revealed.　©　2023　by　the　authors.