The motor driven sprayer includes one rectangular frame, one spray head, one hose, and one water tank on the frame, one rear arm for suspending onto a tractor, one front arm with embedding track, one guide wheel installed on the track, one link rod connected to the guide wheel, one limiting wheel connected to the link rod, one middle spray head support, two movable spray head supports, one distributor, one water pump connected through one filter to the water tank, and one speed variator connected to the driving wheel of the water pump and the power output of the tractor. The motor driven sprayer has simple structure, convenient operation and low production cost.