During the operation of an aviation fuel centrifugal pump, the performance of the pump dropped sharply due to cavitation, which caused cavitation damage near the volute tongue, which seriously threatened the safe and stable operation of the aircraft. According to the characteristics that the cavitation in the volute tongue region occurs in large flow rate, the volute tongue shape of aviation fuel centrifugal pump was improved in this paper, and the influence of the volute tongue shape on the cavitation characteristics of aviation fuel centrifugal pump at 1.2 times of design flow rate was studied. The research shows that under 1.2 times of design flow rate, the critical cavitation number of the improved volute tongue shape is reduced by 7.4% compared with the original scheme. The improved volute tongue effectively suppresses the generation of cavitation in the volute tongue region. The vortex core distribution area is reduced compared to the original scheme. When the cavitation number is low, doubling the axial passing frequency on the pressure pulsation spectrum at the monitoring point of the volute tongue is obviously weakened.