In the structure of rotating piezoelectric energy harvester, the design of the centrifugal force allows the resonant frequency to passively follow the change of the rotational frequency. In this way, a wide frequency band can be achieved by selftuning. However, the performance of the harvester is very sensitive to the parameters. In this paper, the key parameters of the harvester are analyzed and optimized. The EulerLagrange method is used to establish the electromechanical coupling equation. The concept of tuning factor D is proposed. The design of multiple parameters is concentrated into the tuning factor, which can greatly improve the design efficiency of the harvester. The design of the tuning factor is studied by numerical simulation and experiment. Results show that when D≤1, the peak of bandwidth increase decreases with the increase of D. The performance decreases significantly when D≥1. Compared with the noncentrifugal harvester, when D=09, the peak is reduced by 316%. The 6 dB bandwidth is increased from 06 to 7 Hz, which is an increase of 117 times.