The jet characteristic of various nozzles with different structure was researched,and the design principle of nozzle was presented by the simulations of the jet characteristics of nozzles with various structures and geometrical parameters.The simulation results show that the fluid jet polishing system with the cone-shaped and columned nozzle can get a better jet characteristic and the geometrical parameters of nozzle affect the jet characteristics.When the shrinking angle is 13°and the ratio of length to diameter is 4,the issuing velocity of nozzle is well-proportioned and the turbulence intensity is low.This kind of nozzle is suitable to be applied in fluid jet polishing system.