The invention discloses a hydropower-station inclined-shaft excavation and over/under-excavation inspection method, and belongs to the field of hydropower-station inclined-shaft quality control. The method is applied to a Casio-4800 or Casio-4850 calculator. A construction coordinate system of which mileage is x and line width is y is used; and pre-excavation construction lofting (lofting of surrounding positions in pressure steel pipe installation) applied to a hydropower-station pressure pipeline inclined-shaft section, over-excavation or under-excavation inspection after surrounding excavation and processing measurement are mainly considered. Originally, geodetic coordinates are collected through an on-site total station, and then returned to an office, points are displayed on a computer according to the coordinates, then comparison with a design is carried out, and then over/under-excavation is checked; but after the inspection method of the invention is adopted, now an over/under-excavation result is immediately calculated through on-site measurement and the calculator, and the purpose of solving the on-site over/under-excavation problem in time is achieved.