In order to provide farm operation machine for corn and sugarcane at the late growing stage, a high clearance machine with four-wheel diamond arrangement was designed. Gantry structure was adopted with high ground clearance, low gravity center, short turning radius and good stability. To ensure the steering angle of the front wheel which was the same as that of the rear wheel, and the rotation direction was opposite, a set of drag link was designed, so that the turning radius was reduced. An adjusting mechanism consisting of extension tubes and hydraulic cylinder was adopted between side wheel and the central body, the wheel-base could be accurately regulated in a wide range, thus different planting spaces could be adapted, and the compaction on crop roots could also be reduced. The same adjustment mechanism was also used in the height direction of left and right wheels, and the machine could be leveled on the slope, and rollover could be avoided when the machine worked on a large slope. The corresponding hydraulic system and mechanical system were designed for walking drive, adjusting mechanism and auxiliary devices. The test results indicated that the maximum crossing altitude was 2.8 m, the anti-tipping capacity was increased by 2.4 times than that of traditional scheme, the track adjustment range was 0~1 000 mm, and the machine could be leveled on the slope with inclination angle less than or equal to 25°.