Abstract: Two-dimensional numerical model for the cooling channel and electrode in plasma cutting torch was established with FLUENT commercial software,the relationship between the coolant flow field and geometry structure of the electrode was analyzed and the effects of four different electrode structures on the distribution of cooling flow field were investigated. For A-type electrode, there existed a zone where the flowing speed of the coolant was zero. For B-type electrode and C-type electrode, there was a back-flowing zone and zero-speed zone. For D-type electrode,the arc transition in the cone-shaped electrode was beneficial to cooling of the electrode. Meanwhile,the effect of inserting depth of capillary tube on the cooling flow was simulated. When the ratio of inserting depth of capillary tube to the diameter of capillary tube was larger than 0. 5,there existed a zero- speed zone,however,when the ratio was around 0. 2,the distribution of fluid flow field was beneficial to cooling of the electrode.