Abstract: Because of its high cavitation intensity and high cavitation rate, the rotor-radial groove hydraulic cavitation reactor has been widely used in industrial fields such as disinfection and sewage treatment. An arc type of rotor is proposed, and the cavitation performance of the arc rotor and the original rotor at different speeds is analyzed by numerical calculation. The interaction between the stator and the rotor is analyzed, and the influence of changing the installation angle of the arc rotor blade inlet on the cavitation performance of the reactor is studied. The results showed that the arc rotor greatly improved the cavitation intensity and cavitation rate in the reactor at different speeds. In the rotor region, cavitation occurs on the suction surface of the rotor blade, corresponding to the low pressure region. In the stator region, when the rotor blade turns the stator blind hole, the fluid is strongly sheared, the pressure inside the blind hole and the separation area between the inlet and outlet decreases, the vorticity increases, and shear cavitation and vortex cavitation occur. Increasing the installation angle of the blade inlet can greatly increase cavitation intensity and improve reactor performance.