In order to solve the problem of forage harvesting in hilly and mountainous areas, the folding mechanism of the hanging large-width lawn mower was optimized, the operation ability of the lawn mower under complex terrain conditions was enhanced, and the operation efficiency of the lawn mower was improved. In order to expand the swing angle range of the folding mechanism, the size requirements of each component were analyzed and calculated under the condition that the folding mechanism can achieve positive and negative swing of 30°. The ADAMS simulation software calculation showed that the maximum pulling force of the hydraulic cylinder of the folding mechanism was 51600N. It was calculated that the maximum stress value of the rotating arm was 216.67MPa, and according to the theoretical calculation results, a folding mechanism suitable for a 3.2m wide lawn mower was trialproduced. Folding mechanism, a matching hydraulic profiling system was developed, the profiling system adopted the method of providing auxiliary oil source for the lifting hydraulic cylinder, and was connected to the accumulator through a check valve and a stop valve at the oil inlet of the hydraulic cylinder. The initial volume of the accumulator was 2.0L, and the pre-charge pressure was 7.0MPa. The ADAMS-AMESim co-simulation technology was used to simulate and analyze the folding mechanism and the profiling system. The volume variation range of the airbag of the cutter was 0.4~0.7L, and the variation range of the ground pressure of the cutter was 1700~2500N. Finally, the trial-produced profiling system was mounted on the folding mechanism, and a field test was carried out in Sanshan District, Wuhu City, Anhui Province. The results showed that the prototype can successfully complete the folding action of the lawn mower and meet the mechanical and strength requirements under various working conditions. The mower had a swing range of ±30°;the test prototype equipped with the profiling system can smoothly pass through the 250mm high wave convex road, which improved the terrain adaptability of the lawn mower in hilly and mountainous areas, and can be used for hanging mowers. It provided a reference for the design of the lawn mower folding mechanism and the grounding profiling technology of the lawn mower.