The invention discloses a thin-wall pipe material heat conductivity coefficient calculating method adopting a transient heat transfer calculation model and belongs to the field of solid-material thermophysical property measurement. The thin-wall pipe material heat conductivity coefficient calculating method includes: putting forward a new thin-wall pipe heat conductivity coefficient calculating model-a Hot Spring model and giving out a concrete formula; measuring to-be-measured temperature points in the model by applying a temperature sensor, and performing fitting on response data of the measured temperature time to acquire a time parameter sigma; determining the formula of the final Hot Spring model and calculating out heat conductivity coefficient of a thin-wall pipe material according to the slope of the formula. Compared with the prior art, the thin-wall pipe material heat conductivity coefficient calculating method has the advantages that reprocessing of the to-be-measured sample is not needed, experiment procedure is simplified, and precision in measuring the heat conductivity coefficient of the to-be-measured sample of the kind is improved.