Drilling　path　optimization　is　the　key　problem　in　holes　machining.　This　paper　presents　a　swarm　intelligent　approach　based　on　the　particle　swarm　optimization　(PSO)　algorithm　for　solving　the　drilling　path　optimization　problem.　Because　the　standard　PSO　algorithm　is　not　guaranteed　to　be　global　convergence　or　local　convergence,　the　algorithm　is　improved　by　adopting　the　method　of　generating　the　stop　evolution　particle　over　again　to　get　the　ability　of　convergence　on　the　global　optimization　solution.　And　the　operators　are　improved　by　establishing　the　order　exchange　unit　and　the　order　exchange　list　to　satisfy　the　need　of　integer　coding　in　drilling　path　optimization.　The　experimentations　indicate　that　the　improved　algorithm　has　the　characteristics　of　easy　realization,　fast　convergence　speed,　and　better　global　converging　capability.　Hence　the　new　PSO　can　play　a　role　in　solving　the　problem　of　drilling　path　optimization.