Abstract: Abstract: Rice precision hill-drop drilling technique in dry land uses fixed hill spacing to achieve the orderly planting of crops and attain good ventilating and day-lighting effects in the rice field. Meanwhile, the technique is beneficial to improve the root growth and root structure, and increase the lodging resistance. At present, the planting machine in China generally adopts groups of sprockets or groups of gears to change the transmission ratio and realize the adjustment of hill spacing. However, by using the machine available, the adjustment range of hill spacing is very limited. In order to increase the adjustment range of hill spacing and realize the stepless regulation of hill spacing, an automatic electro-hydraulic proportion regulation system was developed based on the programmable logic controller (PLC) and the touch screen, which could realize the real-time adjustment of the hydraulic motor speed and the planting operation together. In the regulation system, the hydraulic unit was mainly composed of liquid pump, hydraulic motor and proportional flow valve and so on. Simultaneously, the PLC ladder diagram procedure was programmed by the Delt WPLSoft V2.37 programming software, and the man-machine interface was developed by using the monitor and control generated system (MCGS) configuration software. Through the man-machine interface developed, the diameter of land wheel and the hill spacing value could be inputted, the initial values and the threshold of proportional flow valves could be set to adjust proportion integration differentiation (PID) parameters, and the adjustment of hill spacing and the monitoring of operation speed could be realized. As demonstrated by the bench test and field test, on one hand, it was found that when working within the speed ranges of 2.8-3.2 and >3.2-3.6 km/h, the qualified rates of hill spacing in both tests had reached 100%, which met the requirements of sowing; on the other hand, when working within the speed range of >3.6-4 km/h, the qualified rates of hill spacing in both tests were 89% and 70%, respectively. According to "The operation quality of the film-covering hill-drop drilling machine" (NY/T987-2006) - the standard of the agricultural industry, within the speed range of >3.6-4 km/h, the qualified rate in the field test was below 80%, and it failed to meet the requirements of the operating quality of film-covering hill-drop drilling. It could be concluded that when rice precision hill-drop drilling technique in dry land chose the type hole-wheel seed-metering device, the effect of hill formation in the field test was influenced to somewhat higher extent by the wind resistance, frame vibration and falling velocity of seeds and so on, and the operation speed should be controlled within the range of 2.8-3.6 km/h, for the higher the speed was, the more obvious the influence on the hill formation performance would be. Both of the results of the bench test and field test demonstrated that the electro-hydraulic proportion regulation system was feasible for the rice hill spacing adjustment. The research can provide the theoretical basis for the hill spacing adjustment technique of planting machine and the technical reference for the related design of planting machine.