Abstract: A new method to calculate thermal conductivity employing Fourier transform is proposed, largely improving the original method in this experiment. The stability and error of the new method are discussed. Causes of error including the finite length of the sample, machining error are analyzed. Error analysis shows that if machining error is lowered, the total error can be kept below 5%. And suggestions to improve the experimental equipment are proposed

Key words: dynamic method of measuring thermal conductivity, Fourier transform, delay theorem