Abstract: This study aims to reduce the violent vibration for the high reliability of the integrated machine for straw return and residual film recycling. A vibration characteristic analysis was carried out to optimize the structural parameters. The modal characteristics of the frame were solved using the Lanczos algorithm on the ANSYS software, in order to obtain the modal frequencies and shapes. The equivalent vibration mechanics model was used to establish the vibration model of the machine. Newton's second law was adopted to analyze the model force. The vibration program of the simulation was constructed to solve the vibration parameters using Matlab/Simulink. A series of measurements of point locations were used to verify the vibration of the machine. The test was also carried out in the conditions of no-load and field harvesting. Some sensors were installed and connected to the YND Data Acquisition Instrument. Vibration data was collected with the time and frequency domains. The results showed that the 1st and 2nd order natural frequencies of the frame were 39.001 and 39.076 Hz, respectively. The modal vibration pattern was that the side panels oscillated back and forth along the y-axis. The vibration intensity under field harvesting was higher than that under no-load conditions. The measurement point 3 vibration amplitudes in the two conditions were 34.93 and 22.36 m/s², respectively, where the difference in the vibration amplitude was 12.57 m/s². The maximum was found in the measurement point 3 of the Y, and Z directions in field harvesting, as well as the measurement point 5 in the X direction of the amplitude. The continuous operation of the stripping device increased the vibration intensity of the machine with less reliability in the field harvesting under the straw crushing device. The straw-crushing device and the stripping device were the main components that contributed to the machine's vibration. The effective values of vibration acceleration were 2.92 and 2.64 m/s², respectively, after test and simulation. The relative error of 9.6% fully met the requirements of mechanical simulation. The spectrum analysis showed that the machine vibration frequency was mainly for the fundamental frequency of the tractor power output shaft, as well as the fundamental frequency and frequency multiplier of the straw crushing device. The large vibration intensity was measured at point 3 of the X, Z directions, and point 1 of the Z direction. There were weld cracks and bolt loose. The measured vibration frequency appeared at 36.13 Hz close to the first two orders of the frame's natural frequency. The modal vibration pattern was easy to stimulate the local resonance in the range of excitation frequency. The orthogonal experiment was adopted to optimize the frame with the thickness of the side plate, the thickness of the main connecting beam tube wall, and the width of the secondary support beam as the object variables, while the 1st and 2nd orders of the frame's natural frequency as the indicators. The optimal parameters were achieved, where the thickness of the side plates was 12.0 mm, the tube wall thickness of the main connecting beam was 6 mm, and the width of the secondary support beam was 70 mm. The 1st and 2nd natural frequencies were 50.700 and 53.322 Hz, respectively, which were higher than the maximum limit of the excitation frequency in the straw-crushing device of 46 Hz. Thus the resonance was effectively avoided. The improved model was verified to significantly reduce the vibration intensity of each measurement point, with a 48% amplitude of the maximum reduction. The transmission of vibration intensity was also significantly weakened, indicating the effective optimization. This finding can provide the theoretical reference for the vibration analysis and structural optimization of the residual film recycling machine.