Disclosed is an agricultural drone system that can adjust pesticide spread in real time using sensor-based crop situation big data analysis. The agricultural drone system which can adjust the pesticide spraying amount in real time using the sensor-based crop situation big data analysis of the present invention is a pesticide spraying drone system for spraying pesticides on a target area, and includes a plurality of spray nozzles for spraying pesticides. A camera for photographing actual crop conditions of crops of the pesticide sprayed area, a thermal image sensor provided on the drone to measure the moisture content of the crops of the pesticide sprayed area, and a crop of the crops of the pesticide sprayed area An image acquisition unit including a multispectral sensor； A memory unit which receives the detected value of the image acquisition unit and temporarily stores the detected value； And a flight controller for controlling flight attitude, speed, and rotation； Image data collected from the camera, the thermal imager, the spectrum sensor repeatedly performed for a predetermined time and a predetermined number of times, and a pesticide spraying amount according to the image information and a crop harvest state change according to the variation of the image information and the pesticide spraying amount is stored. A big data-based pesticide spreading unit including a data database and a pesticide spreading amount analysis unit which provides an optimized pesticide spreading amount by repeatedly analyzing and learning information stored in the big data database and changes in crop harvest state； And a portable terminal configured to display a GIS-linked pesticide spraying target area on a screen and adjust the operation of the drone and the pesticide spraying amount by a user operation. The drone may include analysis information of the big data-based pesticide spraying amount providing unit. It is characterized in that to perform in real time control the pesticide
