Abstract: In order to investigate a new and optimal structure form of star-shaped flow stabilizer, six-ribbed star-shaped stabilizer was selected and five different lengths of star-shaped stabilizer with cross arrangement were designed. Numerical simulations based on CFD were carried out for five types of diversion type fire fighting water cannon with different structures of flow stabilizer. The effect of flow stabilizer structure on the turbulent kinetic energy and axial velocity of the fluid in the fire fighting water cannon was analyzed. And the pressure drop under different arrangement forms was also analyzed. It shows that the installation of flow stabilizer can improve the axial velocity distribution and reduce the turbulent kinetic energy of the inlet and outlet of the fire fighting water cannon, and the forked-row arrangement of flow stabilizer can significantly improve the flow stabilization effect. Among them, the combination of 2, 40 mm long and crossed flow stabilizers is the most favorable to improve the comprehensive performance of the fire fighting water cannon. Under the same volume condition, it is limited to improve the performance of the fire fighting water cannon by shortening the length of the stabilizer and increasing the number of fork rows in the flow stabilizer, and an excessive number of forked rows will cause reverse direction flow and large pressure loss. The research result provides some guidance on the application of star-shaped flow stabilizer within fire fighting water cannons.