Three-coordinate measurement method for throat area of turbine guider

The invention discloses a three-coordinate measurement method for the throat area of a turbine guider. The method comprises the following steps: step 1, obtaining a stacking axis Z axis; step 2, determining a reference coordinate system for measurement; step 3, obtaining a measurement coordinate system X 'Y' Z; step 4, obtaining the area of a throat curved surface 5; a measurement coordinate system is established by adopting the actual morphology of the local blade profile and the case, so that the situation that the measurement coordinate system is established through the theoretical size between the case and the blade is avoided, and the deviation caused by welding and assembly deformation is eliminated; by selecting an approximate throat measurement plane capable of representing a theoretical three-dimensional throat surface, the operability of measurement is improved, more physical throat shape information is obtained through enough discrete measurement points, and the precision of the measurement result