A low specific speed centrifugal pump was selected as the research object, and a method of suppressing cavitation was proposed by arranging rough zone on the suction surface of the blade leading edge. The modified SST k-ω turbulence model and Kubota cavitation model was applied to carry out cavitation numerical simulation on the whole flow area of the centrifugal pump. By comparing the flow field structure, turbulent kinetic energy distribution, velocity vector, cavitation volume change and pressure fluctuation of monitoring points in centrifugal pump impeller with and without rough zone structure under different cavitation numbers, the performance and cavitation suppression effect of rough zone structure on centrifugal pump were analyzed. The research results showed that the rough zone structure had little effect on the head and efficiency loss of the centrifugal pump, and it also did not have a great impact on the operation of the centrifugal pump. After the rough zone was arranged, the flow field distribution in the impeller was improved, the vortex intensity was weakened, and the flow became more stable. The rough zone structure effectively suppressed the initial formation of cavitation bubbles, reduced the energy dissipation caused by turbulence in the initial stage, and also had a certain inhibitory effect on the volume of the cavitation in the stage that cavitation bubbles had a great impact on the head of the centrifugal pump. Under different cavitation numbers, the rough zone structure had little effect on the main frequency pressure amplitude at the impeller inlet, the outer edge of the impeller and the volute separation tongue, and produced varying degrees of disturbance to the pressure pulsation behind the rough zone structure and close to the structure. The structure had certain reference significance for practical engineering applications.