A 3-D model of a sprayer was built with Pro/E，and its finite element model was developed by using Hypermesh. It was imported to ANSYS for free modal analysis. With analysis of vibration characteristic and accuracy of the finite element model, the modal experiment was carried out. Combined with the modal analysis results, the influence of external excitation on the frame was analyzed. It was found that engines first-order and second-order reciprocating inertial force frequency can cause frame resonance. Harmonic response analysis was carried out to obtain the vibration result of the frame. The method of avoiding resonance between frame and engine was proposed. The frame’s displacement response was compared before and after vibration reduction. The results showed that dynamic performance and ride equality of the frame was effectively improved. 