The model and calculation of two most common pipe sections were studied. For straight pipes, a time-domain equation model considering fluid-structure interaction described by partial difference equations was set up. And the time-domain equations were transferred into frequency domain by Laplace transformation, from which an analytical solution was obtained; For curved pipes, the model was directly solved to get an overall solution, also an analytical solution obtained. Then the single-bend pipe model set up by Davidson was taken as an example to simply illustrate the calculation of combination of the two most common pipe sections, and the correctness of the method was also validated by the model. Finally, the factors affect the characteristics of fluid-structure interaction were analyzed by changing the bend radius and angle of curved pipe. The results show that the smaller the bend radius and angle of curved pipe, the lower density the spectrum curve, which shows that coupled vibration has the less dramatic.