Aiming　at　the　problem　that　it　is　difficult　to　confirm　the　parameters　of　the　PID　controller　and　the　parameters　can　not　be　changed　once　identified,　an　intelligent　PID　control　method　is　proposed.　According　to　the　size　of　the　system　error,　this　algorithm　controls　the　system　with　different　subsections　of　different　parameters,　by　using　the　particle　swarm　optimization　(PSO)　to　optimize　the　parameters　of　the　PID　controller　to　solve　the　problems,　such　as　lag,　time-variety　and　nonlinearity.　A　new　evaluation　function　including　the　system　adjusting　time,　rise　time,　over-shoot,　and　system　error　is　defined.　A　group　of　parameters　of　the　PID　controller　that　minimize　the　evaluation　function　is　calculated　rapidly　by　searching　in　the　given　controller　parameters　area.　Numerical　simulations　show　that　the　controller　can　easily　be　applied　to　the　first-order　and　second-order　systems　with　time　delay　and　its　performance　is　also　better　than　the　classic　PID　optimized　by　PSO.　©2010　IEEE.