Abstract: In order to better fit the cavitation test data of the centrifugal pump,this paper sets up a closed horizontal centrifugal pump cavitation test rig and collects the cavitation test data. Firstly,three,four,five and six times of normal polynomial fitting are performed on the cavitation test data. The fitting effect of the five-order polynomial fitting method on the cavitation test data is better,but with the increase in fitting times,the oscillation of the cavitation curve becomes more serious. Secondly,PSO and WVPSO algorithms are used to perform piecewise polynomial fitting of the cavitation test data respectively. By comparing the fitting results of the two algorithms,it is found that WVPSO algorithm has a better fitting effect on the data,and it can eliminate the oscillation phenomenon of the cavitation curve after polynomial fitting,making the cavitation curve smoother.