The laboratory simulation of the sowing depth consistency control system is mostly testing parallel four-bar linkage or up-and-down movement due to surface fluctuation, while the actual farmland surface morphology varies irregularly in both elevation and slope. In view of this, a farmland-terrain simulation system suitable for rugged topography is designed to study the irregularities of farmland surface morphology led by both topographic fluctuation and terrain tilt. The system consists of terrain simulation mechanism, hydraulic system, control system, etc. The terrain simulation mechanism is connected to the rack through hydraulic cylinder to simulate farmland surface fluctuation. The hydraulic system controls the hydraulic cylinder to drive the terrain simulation mechanism through the electro-hydraulic proportional directional valve. The control system controls hydraulic system and drives the terrain simulation mechanism according to the topographic data. The physical parameters of the terrain simulation mechanism are achieved by mathematic modeling of the profiling mechanism and building the geometrical relationship between the telescopic gradient angle and the expansion or contraction of the hydraulic cylinders. Based on the force analysis of hydraulic cylinder, the parameters of the hydraulic system are determined by theoretical calculation. In the simulation at 2.0m/s operating speed, the average elevation error is 1.61mm and the average slope error is 0.56°. The experimental results indicate that the system showed rapid and accurate performance on terrain elevation and slope simulation, and it can meet the requirements of farmland terrain simulation.