To meet the demands of self-powered monitoring system for rotating machine and improve the reliability and effective working frequency band for existing piezoelectric energy harvesters，a Rotary Piezoelectric Energy Harvester （PEH） is introduced，which is based on a moving cam with indirect and limited excitation. The system structure and working principle of the energy harvester are introduced and its dynamic response model is established. In this way，the influence of the excitation magnets ratio，the cam lift and angle to the excitation force form/magnitude，the deformation of the piezoelectric vibrator/output voltage and the harvester bandwidth are obtained by simulation and experiment. The research results show that the indirect excitation of the cam can effectively limit the amplitude/output voltage and avoid the obvious resonance peak of the amplitude-frequency characteristic curve；When other conditions are given，the effective bandwidth of the piezoelectric vibrator deformation/output voltage increases as the excitation magnet ratio decreases and the cam angle increases（30°-45°）. As the cam lift increases，the piezoelectric vibrator deformation amount/output voltage increases，and the effective bandwidth decreases. When magnet ratio is 0.25，lift angle is 40°，excitation distance are 2/3/4/5mm，the effective speed range is 212.8/67.2/67.2/44.8 r/min for the output voltage is 20/40/60/70 V；In addition，there is an optimal load of 70 kΩ to maximize harvester output power（9.66 mW）.