Abstract: This paper introduced the method, instrument, location and technique procedure of reservoir cross-sectional surveying in Ertan Hydropower Station, inquired into quality control and data processing for harvest of reservoir cross-sectional surveying, application of cross-sectional surveying technology in calibrating reservoirs’ capacity and analyzing sediment accumulation. It can provide a new method and thinking of cross-sectional survey and calibrate the reservoirs’ capacity for large and medium scale hydropower station in our country.