The invention discloses an agricultural unmanned aircraft controlled by a Beidou satellite and a GPS (global positioning system). The agricultural unmanned aircraft comprises an aircraft body and a ground control system, wherein the ground control system comprises a task planning and control station, a power supply cart and an antenna system; the aircraft body comprises an airplane body, a propelling device, a chemical spraying device, a flight manipulating device, a power supply system, an airplane-borne navigation device and a flight data terminal; the task planning and control station comprises a task planning device, a control and display control platform, an image and remote measuring facility, a computer, a signal processor, a ground data terminal and a communication device; the airplane-borne navigation device comprises a GPS receiver, a Beidou receiver and a navigation control system; the GPS receiver comprises a GPS receiver antenna unit, a GPS receiver host unit and a power supply; the Beidou receiver comprises a receiving antenna, a transmitter and a Beidou receiver host unit; the navigation control system is used for preprocessing the GPS navigation information and Beidou navigation information and uniformly changing a coordinate system and a datum point.