Space vector data storage method based on point M value and coordinate system conversion system

The invention provides a space vector data storage method based on a point M value and a coordinate system conversion system. The space vector data storage method comprises the steps that each inflection point of each space element of space vector data has a unique corresponding M value; wherein the conversion parameter number of the inflection point is recorded in the M value, namely the conversion parameter number adopted when the first geographic coordinate system is converted into the WGS-84 geodetic coordinate system; pre-establishing a dictionary file for the space vector data and binding the space vector data file; recording a conversion parameter number recorded by the M value of the inflection point, a corresponding coordinate conversion method and a corresponding coordinate conversion parameter in the dictionary file; converting the space vector data from the first geographic coordinate system to a WGS-84 geodetic coordinate system; and converting the coordinate system from aWGS-84 geodetic coordina