A weeding robot that could work on intra-row weeding and inter-row weeding simultaneously was proposed to improve weeding efficiency. The robot adopted suspension structure for the optimization of field adaptability. Physical prototype of the robot was developed and manufactured. According to the obstacle-crossing analysis, the suspension structure was of good adjusting function. The obstacle navigation characteristic of weeding robot was simulated by ADAMS. Its ability of crossing obstructions in convex, concave and oblique lands was researched and simulated. The results showed that the robot could move on these three typical lands with excellent adaptability.