Under the background of rapid development of intelligent agriculture with information, knowledge and equipment as the core, intelligent robots have gradually replaced the traditional methods of farmland information collection and received more and more attention. In order to adapt to the complex agronomic conditions such as paddy field walking and different ridge widths, an upland gap four-wheel drive farmland information acquisition robot with adjustable wheel spacing was designed. By using SolidWorks, the overall structure was designed and analyzed and parts were selected. The trial-production of the robot was completed. A combined navigation and path tracking control system based on GNSS and INS was designed. The results showed that the four-wheel drive mode of the robot had good speed consistency and strong anti-interference ability. The error rates of the ground gap and wheel pitch adjusting mechanism were 1.33% and 0.73%. A comprehensive path tracking algorithm based on double tangent circle line was proposed. Compared with the pure tracking algorithm, the amplitude of oscillation was reduced by 75.0% and the convergence time was reduced by 28.5%. The average lateral error of the robot linear path tracking was 6.8cm, and the average convergence time of right-angle turns was 25.6s. The maximum speed of the robot was 1m/s, and the average time of single point information acquisition was 24.5s. All kinds of data collected by the sensor met the application requirements. The information acquisition robot can complete the work of farmland information acquisition quickly, efficiently and accurately under the complex conditions of paddy field.