This paper is referred to other literature on properties of metal fatigue testing methods and data analysis procedure methods. According to high cycle fatigue testing, double-wall-brazed-tube is loaded with different stimulated vibration force by shaking table and is forced to vibrate. In the experience, strain of key parts is measured with Electrical resistance Strain measurement Methods. By curve fitting of experimental data, we gain the fitting function of the specimen’s fatigue life and draw its S-N curve. In accordance with the analysis of experimental data and S-N curves, it is concluded that fatigue properties of metallic materials can not fully reflect fatigue properties of a specimen and that the cross-sectional size of a specimen has much effects on its fatigue life.