The utility model discloses an automatic target variable pesticide sprayer, comprising an image detecting device, a spraying device, an assistant signal device, a pesticide liquid supply device and a computer; wherein, the image detecting device, the spraying device and the assistant signal device are respectively connected with the computer, while the pesticide liquid supply device connects to the spraying device; by use of the cooperate working of the image detecting device, the assistant signal device and the computer, the utility model performs automatic target pesticide spraying according to the existence and inexistence of pesticide target; the spraying device consists of more than one spraying units, and each spraying unit consists of more than one spraying poles which are provided with more than one nozzles of the same spraying quantity and switches. Each spraying pole nozzle has different spraying quantity, whose switch realizes connection with the computer by use of the pipe line; while the computer controls the spraying poles by use of the switch, achieving different spraying quantity combinations, and consequently, the utility model is able to adjust the spraying quantity according to the characteristic changing of the pesticide target and the changing of the unit moving speed, thereby achieving the aim of variable pesticide spraying.