Abstract: To enhance operational reliability, shredding quality, and suppress vibrationion of straw crushing device, finite element simulation method was employed to systematically analyze mechanical and vibration characteristics of different structural moving blades．A statical analysis under extreme operating conditions was conducted to compare bending resistance of straight-edged and serrated blades．Results have shown that the maximum equivalent stress of serrated blade was only 9.43 MPa, with minimal deformation（0.0023 mm）, while the maximum equivalent stress of straight-edged blade reached 851.51 MPa, far exceeding material's yield limit and posing a significant failure risk．Under conventional operating conditions, a comparison between triangular, isosceles trapezoidal, and rectangular serrated blades has revealed that triangular serrated blade exhibited extremely severe stress concentration at cutting edge, which did not meet safety requirements．Results from modal analysis and prestressed modal analysis have revealed that fundamental frequency（approximately 517 Hz）of studied blade structure was much higher than operational excitation frequency, and operational load had a minimal impact on its natural frequency（variation <0.1%）, indicating that structural dynamic characteristics were stable and free feom resonance risk．A comprehensive analysis has indicated that adopting a serrated blade design and avoiding geometries prone to stress concentration, such as triangular shapes, is an effective approach to optimizing moving blade structure, ensuring cutting quality, and maintaining overall machine stability．A direct theoretical basis and optimization direction have been provided for highly-reliable, and low-vibration moving blades for straw shredding design．