To　accurately　evaluate　the　dynamic　elastic　modulus　(E-d)　of　wood　in　ancient　timberwork　buildings,　the　new　materials　of　larch　were　used　as　the　research　object,　and　the　stress　wave　nondestructive　testing　method　was　used　to　determine　it.　Based　on　nondestructive　testing　data,　this　paper　proposed　a　method　for　predicting　the　E-d　of　larch　using　the　principle　of　information　diffusion.　It　selected　the　distance　(D)　from　the　bark　to　the　pith　in　the　cross-section　of　the　wood　and　the　height　(H)　from　the　base　to　the　top　in　the　radial　section　of　the　wood.　The　fuzzy　diffusion　relationships　between　the　two　evaluation　indexes　and　the　E-d　were　established　using　the　information　diffusion　principle　and　the　first-and　second-order　fuzzy　approximate　inferences　in　the　fuzzy　information　optimization　process.　The　calculation　results　showed　that　the　dynamic　elastic　modulus　model　constructed　by　the　information　diffusion　method　can　better　predict　the　E-d　of　larch.　The　coefficient　of　determination　between　the　measured　value　and　the　predicted　value　of　the　E-d　was　0.861,　they　were　in　good　agreement.　The　weights　of　the　two　influencing　factors　were　0.7　and　0.3,　respectively,　the　average　relative　error　of　the　fitted　sample　data　was　the　minimum,　which　was　8.55%.　This　prediction　model　provided　a　strong　basis　for　field　inspection.