Aiming to address the issue of spray boom vibration seriously affecting operation quality in complex field environments, the vibration transmission characteristics of the "excitation source - frame - spray boom" structural chain was investigated. Using a 3WPZ - 1800G high-clearance sprayer as the research object, a method combining experimental testing and operational transfer path analysis (OTPA) was employed. Vibration response data were acquired by conducting three types of tests: static engine excitation, unilateral impulse response, and field driving excitation. Triaxial accelerometers were arranged at eight key measurement points to capture data under varying liquid loads (0 L, 600 L,1 200 L, 1 800 L), engine speeds ( 800 r/min, 1 200 r/min, 1 600 r/min), and driving speeds (6 km/h, 8 km/h, 10 km/h). The results indicated that under static load conditions, engine excitation had a limited impact on the spray boom, with high-frequency components (greater than 40 Hz) decaying rapidly along the transmission path. Under unilateral impulse excitation, the spray boom end exhibited a typical "whiplash effect", with a peak acceleration of 40.18 m/s2, which was 8.6 times that of the frame measurement point;the first-order bending mode frequency of the boom was approximately 1.97 Hz. Under field driving conditions, the acceleration RMS value at the left end of the spray boom was increased by 310% compared with flat roads, and the dominant vibration frequency was decreased from 12. 20 Hz to 2. 13 Hz. The coupling between low-frequency road excitation and the low-order mode of the spray boom was identified as the root cause of vibration deterioration. OTPA analysis revealed that under typical field conditions (1 200 L load, 8 km/h driving speed), road excitation contributed 50. 88%, liquid sloshing 28. 53%, and engine excitation 20. 59%. The coupling index (CI) in the main liquid sloshing frequency band (0. 5 ~5 Hz) reached 0. 462, indicating a significant synergistic amplification effect between road excitation and liquid sloshing. Based on the analysis of multi-source contributions, an active-passive synergistic control strategy featuring "passive optimization for resonance suppression and active control for low-frequency tracking" was proposed. The research results can provide a theoretical basis for the suspension optimization and vibration control of high-clearance sprayers.