The invention provides a high-precision monitoring method for a three-dimensional displacement track of a power transmission line tower footing. The high-precision monitoring method comprises the steps of: firstly, defining a coordinate system based on the center of the upper surface of the tower footing, and drawing an initial track of the tower footing; measuring a three-dimensional high-precision displacement vector at the ground surface of the tower footing by adopting a Beidou satellite positioning device; adopting a three-dimensional inclinometer to measure an inclination angle and an inclination direction of the tower footing; adopting a compass for measuring a torsion angle of the tower footing in the horizontal direction, measuring an included angle between a line route and a CGCS2000 coordinate system, performing coordinate transformation and solution on measurement data of the sensors to obtain displacement vectors of all central points and vertexes of the tower footing, andredrawing to obtain a three-dimensional deformation track of the tower footing according to a 1-4 h monitoring period. The high-precision monitoring method can monitor three-dimensional displacementsettlement as well as inclination and torsional deformation of the tower footing, periodically draws the three-dimensional displacement deformation track of the whole tower footing, and reflects the foundation bottom displacement and settlement conditions, so as to evaluate the stress condition and the structural stability of the whole tower footing.