The invention relates to a determination method for a rock structural surface reference plane, and belongs to the technical field of rock and soil mechanics. The method comprises the steps that a three-dimensional white-light scanner is adopted for scanning a rock structural surface to obtain point cloud data of the rock structural surface; then, the MATLAB software is used for reading in the point cloud data of the rock structural surface, and the neutral reference plane of the rock structural surface is recognized and determined on the basis of the neutral reference plane determining principle; finally, according to the reference plane equation, the central point O' of the neutral reference plane is determined, a translation matrix M and a rotation matrix R are constructed, and furthermore, the MATLAB software is used for obtaining point cloud data of the rock structural surface on the reference of the neutral reference plane. According to the determination method, the neutral reference plane of the rock structural surface can be recognized and determined, the point cloud data of the rock structure surface on the reference of the neutral reference plane are obtained, and the problem that the rock structural surface cannot be directly and quantitatively described by point cloud data obtained through three-dimensional white-light scanning is effectively solved.