The present invention relates to a method and system for estimating an autonomous travel position of an unmanned tractor, and is capable of securing precise position data using a low-cost multiple GPS.According to the present invention, there is provided a method of estimating a position, comprising: obtaining coordinates of each vertex of a GPS data triangle as a triangle by receiving current coordinates from respective GPS receivers installed at three positions in an unmanned tractor Computing coordinates of the center of gravity of the GPS data triangle from each of the vertex coordinates of the GPS data triangle Generating a range data triangle that is a virtual equilateral triangle having a length between one side of the GPS receiver while the origin is a center of gravity coordinate Parallel translation of the GPS data triangle so that the center of gravity coordinates of the GPS data triangle and the center of gravity coordinates of the range data triangle coincide Wherein the range data triangle is rotated with respect to the center of gravity in a state where the GPS data triangle and the center of gravity coordinates of the range data triangle coincide with each other at an origin and the angle data vertices of the GPS data triangle and each corner data of the range data triangle Calculating three rotation angles at which the sum of the distances between the two is minimum The New GPS data triangle is set such that the center of gravity of the New GPS data triangle coincides with the center of gravity of the GPS data triangle before the parallel movement. Translating And considering each of the vertex coordinates of the translated New GPS data triangle as the corrected coordinates of the GPS receiver.본 발명은 무인 트랙터의 자율주행용 위치 추정방법 및 시스템에 관한 것으로, 저가형의 다중 GPS를 이용하면서도 정밀한 위치데이터를 확보할 수 있도록 한 것이다. 이러한 본 발명 중 위치 추정방법은, 무인 트랙터에서 정삼각형을 이루도록 세 곳에 설치된 각각의 GPS 수신기로부터 현재 좌표를 제공받아 삼각형인 GPS 데이터 삼각형의 각 꼭짓점 좌표들을 얻는 단계 상기 GPS 데이터 삼각형의 각 꼭짓점 좌표들로부터 상기 GPS 데이터 삼각형의 무게중심 좌표를 산출하