The invention discloses a method for identifying a graph dynamic relationship, which is used for performing relationship identification on graphs drawn by a mouse and input into a computer. The types of the graphs comprise point, line or circle; when the current graph input into the computer through a single click of the mouse is a point, whether former graphs exist under the current graph or not is judged; if the former graphs do not exist under the current graph, the current graph is judged to be a free point; if the former graphs exist under the current graph, the number of all the former graphs under the current graph is extracted, and the former graphs are processed respectively according to the number to identify overlapped points, points on a line, and points on a circle; when the current graph input into the computer through movements of the mouse is a line, whether the former graphs exist under the current graph or not is judged; if the former graphs do not exist under the current graph, the current graph is judged to be a free line; and if the former graphs exist under the current graph, and a judgment is performed according to the position of the terminating point of the movement of the mouse during drawing the current graph, wherein if the type of the former graphs is line, whether the current graph is a center line or a perpendicular line of the former graphs is judged, and if the type of the former graphs is circle, whether the current graph is a tangent line of the former graphs is judged.