The vibration of the header for 4LL–1.5Y combined harvester has been studied by the ANSYS workbench simulation and the vibration experiment. The model frequencies and shapes of the header frame were obtained by the simulation in ANSYS workbench. The results showed that the two sides and the entrance floor of the header frame deformed easily while the combine harvester vibrating. Using the triaxial acceleration instrument and the CoCo–80 dynamic signal analysis system, the acceleration signals of the important parts of the header frame were measured separately, and the vibrations under different working conditions, like low speed (700 r/min), middle speed (1 200 r/min), high speed (1 800 r/min), were tested in the experiment field. The data showed that the acceleration in the horizontal direction as 2–4 times as that the other two directions, and the vibration mainly occurred in the horizontal direction. Additionally, the vibration of the leaning transporter was very serious, with the high value of 97.28 m/s2. Compared the results of the ANSYS workbench simulation with the experiments, the excitation frequency of 20 Hz and 22 Hz, which had great impact on the vibration of the header, mainly appear near the model frequency of 18.679 Hz for the header frame.