Abstract: A simple and fast method to calculate the second-order wave force on an axisymmetric body is studied, and the results of the vertical cylinder and the truncated cylinder’s second-order wave force are attained. The results obtained with the other three different theoretical formulas are compared to verify the correctness of this method. Because this method does not involve a free surface infinite integral, and has a simple expression and high computational efficiency, it is more suitable for fast calculating second-order wave forces caused by second-order potential.