The invention discloses an orthogonal plane calibrating method and an orthogonal plane calibrating system of relation between a laser distance measuring device and an end of a mechanical arm. The laser distance measuring device is fixedly disposed on the end of the mechanical arm, and the calibrating planes, which are orthogonal to each other, are disposed in the space. Under the driving of the rotating translational motion of the mechanical arm, the posture of the laser distance measuring device can be changed, and the distance d measured by the laser distance measuring device can be used to solve the translational vector r and the unit direction vector v of the laser beam, and the calibrating of the space transformation relation between the laser distance measuring device and the end of the mechanical arm can be completed. The reconstruction of the point x of the object in the three-dimensional object can be realized according to the x=r+dv. The transformation relation between the coordinate system of the end of the mechanical arm and the coordinate system of the laser distance measuring device can be determined clearly. By using the calibrating plane as the orthogonal plane and adopting the non-linear optimization method, the coplanarity of the points can be fully used as the constraint condition to solve the calibrating problem of the space transformation relation, and therefore the constraint condition can be added, the errors can be reduced, the noise interference can be reduced, the robustness and the easy implementation of the method can be improved, and the calibrating precision of the space transformation relation can be improved.