Positioning and machining method for newly-added hole of steam turbine

The invention discloses a positioning and machining method for a newly-added hole of steam turbine, which comprises the following steps of: designing the number, the diameter and the distribution position of the holes, designing a number hole sample plate, and arranging a plurality of number holes in one-to-one correspondence to the positions and the sizes of the designed holes on the number hole sample plate; mounting the number hole sample plate on an air cylinder, and enabling the number holes and the designed holes to be in one-to-one coaxial correspondence; and forming holes by drilling down the number holes into the air cylinder using a drilling device. The method has the beneficial effects that the hole number sample plate is aligned to a designed hole, and drilling equipment can be guided, so that a drill bit of the drilling equipment is aligned to a designed temperature measuring hole, the hole meeting the design requirements can be machined, the method is easy to operate, the number of used auxiliar