Abstract: To master the internal damage of ancient architecture wood members, by employing two nondestructive testing methods including stress wave and impedance instrument, elm and cypress wood specimen which were different damage types or different internal defect area was tested. Then in this paper a combinatorial model to forecast internal defects of ancient architecture wood members were established based on Shapley value. Results show that Stress wave can get 2D graphics of detection section quickly, and error rate is higher when internal defect is smaller. The stress wave error decreases when internal defect is more than a quarter. Impedance instrument can accurately judge positions and damage types for internal defects under single path. The impedance instrument test results are more accurate when internal defect of wood members is small, internal defects area is proportional to impedance instrument error when increase. Applying the Shapley value method, the weight of stress wave and impedance instrument in the combination forecast model, was determined by distributing the total combinatorial error, then a combinatorial forecast model was establised. The results suggest that combinatorial forecast error is less than 10, and detection accuracy is higher than that of the single test results. The research can help to detect method from qualitative to quantitative analysis for practical engineering repair reinforcement scheme and provide effective data support.