Abstract: A non-contact profile modeling spray position control system based on single chip microcomputer was designed according to the principle of profile modeling spray, which controls step motors to drive nozzle groups so that the nozzles spray at a precise spray distance according to the actual shape of fruit trees measured by ultrasonic distance sensors. The self-adaptive fuzzy control program was designed to adapt to the uncertainity of targets and environment of spray, and step motors driving nozzles are controlled by DPWM (digital pulse width modulation) mode. The experiment results showed that the system was suitable for the profile modeling sprayer.