Abstract: In order to study the propagation property and defect detection ability of the torsional modes in different shapes of pipelines with defects, in this paper, a finite element model of pipeline with defects is established. The numerical simulation of T (0,1) modal guided wave propagation in the straight pipeline and the elbow is carried out by finite element software ABAQUS. The sinusoidal signal modulated by Hanning window is used to excite the T (0,1) modal signal. The results show that the lowest order torsional mode is suitable for pipeline defect detection. Moreover, the T (0,1) modal guided wave of 50 kHz is sensitive to the defects of the straight pipeline and the elbow. In the position corresponding to the defect, the guided wave has the greatest echo amplitude and the more concentrated energy.