The invention discloses a multi-basin typical hydrological year selection method based on the power generation capacity of a hydropower station. The method includes: according to the power power generation capacity of each hydropower station in the area year by year, calculating the annual total power generation of the hydropower station group in the region; drawing an annual total power generation capacity empirical frequency curve of the hydropower station group in the region; according to an annual total power generation capacity empirical frequency curve of the hydropower station group inthe region, deriving an annual total power generation capacity theoretical curve of the hydropower station group in the region; and then obtaining a typical annual total power generation capacity value of the hydropower station group in the region according to the annual total power generation capacity theoretical curve and the design guarantee rate of the hydropower station group in the region, and finally calculating a typical hydrological year of the hydropower station group in the region according to the typical annual total power generation capacity value of the hydropower station group in the region and the annual total power generation capacity of the hydropower station group in the region. According to the method, the multi-basin hydropower station group in the region can be used as a whole, the correlation and complementarity of incoming water among basins are considered according to the set output characteristics of the multi-basin hydropower stations, and the typical hydrological year is accurately selected.