In order to research dynamic natures of a knife-shape-tooth three star-wheel loading mechanism, both mechanical model and solid model of the star-wheel loading mechanism are established by means of updated-Lagrange method and ANSYS software, and the equivalent stress cloud map and displacement respond curves of the star-wheel at different vibration frequencies are obtained through harmonic response analyses. Modal analysis shows that the star-wheel loading mechanism does not take pace resonance when the vibration frequency locates between 2Hz and 2.6Hz, and the star-wheel works stably when the rotation speed is from 40r/min to 52r/min. These study conclusions lay a theoretical foundation for improving the design of a knife-shape-tooth three star-wheel loading mechanism and perfecting its dynamic behavior.