Abstract: The paper presents a linear swing welding algorithm based on the principle of space transformation. The three-dimensional swing welding problem is simplified to the two-dimensional space by establishing the swing base plane, after solving the basic swing point in the base plane, the transformation matrix of the swing plane and the base plane can be solved using the teaching parameters. The basic swing point is mapped to the swing plane by the transformation matrix to obtain the final trajectory for the swing welding. The simulation results showed that the algorithm possesses more input parameters and a quick speed for the solution of trajectory. It is a swing welding algorithm with practical value.