The invention relates to a method for detecting the initial position of a rotor of a static frequency-conversion starting motor of a pumped storage power station, comprising the following steps of: judging primary excitation time of the rotor through the AD sampling of the voltage of a machine end line; calculating three-phase voltage in a static coordinate after the primary excitation time of the rotor is discovered; calculating the magnetic flow of the rotor in the static coordinate through a self-adaption magnetic flow regulating algorithm; and solving a position angle of the rotor througharc tangent, wherein the position angle of the rotor is an initial position angle of the rotor when the position of the rotor is stable. The invention judges the primary excitation time of the rotor through reasonable arrangement and provides the endurance for accurately starting integral operation; a self-adaption magnetic flow regulator can fast and accurately calculate the position of the rotor, not only eliminate DC component inside a passage, but also greatly enhance the calculation accuracy of the position of the rotor, and the calculation accuracy and the calculation time of the position of the rotor are controllable because the integral algorithm is adopted; in addition, in order to ensure the accuracy and the position of the rotor, a filtering judging algorithm is added into the algorithm, thus the judging accuracy of an initial value is greatly enhanced.