The invention discloses a rotating speed measuring method which includes acquiring satellite related peak data sequences of at least antenna, wherein the acquisition period is delta t; carrying out rapid Fourier transform on each satellite related peak data sequence to obtain frequency spectrum sequences F(s); respectively calculating the maximal value of each frequency spectrum sequences F(s), and obtaining s corresponding to the maximal value, solving the rotating speed of the antenna, n=s/delta t, by using the obtained s, and calculating the average values of n. The rotating speed measuring method can calculates the rotating speed of a low-speed rotation body and a high-speed rotation body, and the calculated rotating speed is highly accurate.