Abstract: The model data of forming process are expressed by STL model, and the hierarchical algorithm is the main way to obtain the data.According to the existing equipment of welding cylindrical coordinate, proposed a hierarchical algorithm to simplify the model on the basis of summarizing the current mainstream hierarchical algorithm.Delete and sort the triangular mesh and then build a relationship between them step by step.Finally, a completely valid intersection sequence is selected.This algorithm reduces the memory resource consumption and improves the efficiency.It is proved that the algorithm is stable and feasible through software simulation and multi layered test.

Key words: welding, hierarchical intersection algorithm, sequence, simulation