Abstract: Self-propelled machines running in farm field have to be designed distinctive structure and walking device to adopt ground condition variously and special demand of plants.Taking five typical farm machines as examples such as crawler tractor in pivot steering，self-propelled sprayer，automatic sprinkler，high-speed transplanter and hillside combine harvester.Relationship between structural form and job requirements was analyzed.Working principle and structural characteristics of 5 walking devices including multi-track，high clearance，multiple unit axial combination，water field wheel and level adjustment were discussed.