In order to figure out the effect of the nozzle structure to the jet fluid, and provide some references for choosing the appropriate nozzle, by used two typical kinds of nozzles, the conical nozzle and the straight conical nozzle, as the research objects, and synthetically used ICEM CFD gridding with ANSYS FLUENT fluid analysis software, the jet fluid of these two kinds of nozzles is analyzed according to the basic theory of CFD. The results show that: under the same initial conditions, the conical nozzle has a higher outlet speed, dramatic changes in speed and longer isokinetic core zone of the flux than that of the straight conical one. However, the straight conical nozzle has a more stable speed, and negative pressure is easily occurred due to bottleneck phenomena in short pipes. Through experiments, the simulation results are demonstrated once more.