This article adopts an orthogonal experimental design method to establish a four-factor three-level experimental group by varying the structural parameters at the nozzle outlet, including the number of orifices, orifice diameter, distribution circle diameter, and inclination angle of the base. The three-dimensional jet flow field in the jet pipe was numerically simulated. Through the use of the entropy generation method, Q-criteria, range analysis, and significance test, the working characteristics of the jet pipe were thoroughly investigated. The results show that the orifice diameter has a significant impact on the axial force acting on the jet pipe, while the number of orifices has a minor effect. The distribution circle diameter and inclination angle of the base have very little influence. The final confirmed optimal combination of nozzle structure parameters is as follows: the number of spray holes is 40, the diameter of each spray hole is 1.5 mm, the distribution circle diameter is 22 mm, and the inclination angle of the bottom cover is 30 degrees.