A　set　of　reformulated　theoretical　formulas　was　developed　to　measure　the　relationships　between　moisture　content　(MC)　and　stress　wave　propagation　velocity,　dynamic　modulus　of　elasticity　(E-d),　and　modulus　of　stress-resistograph　of　the　wood.　The　theory　of　wood　science,　elastic　mechanics,　wave　science,　and　stress　wave　propagation　were　used　as　the　theoretical　basis.　Using　larch　as　the　material,　both　stress　wave　and　micro-drilling　resistance　technologies　were　used　to　study　the　timber　property　changes　under　different　moisture　contents.　The　results　showed　that　when　the　MC　of　wood　did　not　reach　the　fiber　saturation　point　(FSP),　the　wood　property　decreased　sharply　with　increased　MC.　However,　the　study　also　found　that　when　the　MC　of　wood　was　higher　than　the　FSP,　the　wood　property　decreased　with　increased　MC.　In　addition,　the　experimental　results　showed　that　the　variation　trend　calculated　by　the　new　set　of　theoretical　formulas　was　consistent　with　the　numerical　variation　trend　measured　by　the　experiment,　and　the　coupling　effect　of　stress　wave　and　micro-drilling　resistance　was　high.　This　set　of　theoretical　formulas　can　provide　a　reference　for　the　research　on　nondestructive　testing　and　performance　evaluation　of　ancient　building　timber.