An electric control system of sprayer was designed, which was driven by pure electric power and realized the unmanned selfpropelled function. The STM32F103ZGT6 microprocessor was used as core and KeilμVision5 development platform was adopted in the system. Based on modular thinking, the development of sprayer power system, network communication system, steering system and spraying system was respectively carried out to realize remote control, precise walking and intelligent spraying. The field test results illustrated that when the sprayer was steered at speed of 2~4km/h, the maximum rotation angle of the outer wheel was 23°, the minimum turning radius was 1.45m, and the turning path had no deviation, the steering was reliable. The average offset was 2.42m when the sprayer was straight running for 50m, the average deviation was 4.84cm/m, the offset was small, and the sprayer can be accurately controlled to drive by the route through the remote control. When the sprayer was spraying at top speed of 10km/h, the effective climb gradient was less than 25°. The sprayer was tested in field, the maximum cruising time was greater than or equal to 5.50h when the driving speed was 2~10km/h with sufficient power storage. In the maximum battery life, the number of dropped calls of network communication was no more than 1, and the communication reliability was good. When the remote control distance of the sprayer was in the range of 0~500m, the speed adjustment control, steering control and the response time of liquid medicine electromagnetic valve control were all less than 0.4s. The general working condition of field operation was satisfied. This control system can effectively realize the separation of man and machine, ensure the safety of operators, suitable for most small farms, and effectively improve the operation efficiency of wheat plant protection.