The invention discloses a trace extraction method based on a discontinuous surface boundary three-dimensional space constraint intersection line, and provides an ARCG method based on a three-dimensional
point cloud, realizes simultaneous extraction of a single surface and a contour part of a structural surface by dynamically adjusting a parameter threshold value, quantifies and discusses
goodness of fit of different structural surface models according to an
area ratio, and provides a trace extraction method based on the boundary three-dimensional space constraint intersection line of the discontinuous surface. And finally, selecting a
parallelogram as an optimal model. Further searching an intersection line between the contour points of the intersection pairs of the structural surfaces by virtue of a space intersection relation of the model, and dynamically dividing the intersection line to keep the geometric characteristics of the structural surfaces. And finally, connecting the intersecting lines of the same
structural plane through a bidirectional
weight growth graph theory to form a final trace result. According to the method, the feasibility is verified through data of two slopes, case results show that compared with an existing method and
point cloud processing software, the method can achieve extraction of complex traces and keep good
connectivity, and the calculation efficiency can be improved by 96.6% while the traces are accurately extracted. Therefore, the method provided by the invention can provide a new method thought for digital characterization of rock
mass structural plane parameters.