Abstract: The fluid field and temperature field in plasma torch were simulated by using the finite element analysis.The influence of the torch structure on the velocity of water flow and the turbulence formation was analyzed.On the basis of the analyzed results the temperature field under different fluid field conditions were calculated.By checking computations of the temperature rise at some key location in the torch,it has been found that the cooling effect of the plasma torch can be obviously improved by changing the water flowing route and water entering direction,and which need not increase the flow volume of the cooling water.The calculated data provided a foundation for the torch design and improvement.