The invention discloses a real-time power angle measuring method of a generator. The method takes GPS or Beidou pulse per second as standard, and samples electricity at a generator end and a key pulse impulse signal with high density at equal intervals. Through performing corresponding anti-interference treatment on the collected signal, high-precision synchronous phasor quantity and key phase impulse position information can be acquired, thereby acquiring the high-precision real-time power angle of the generator. The method has the advantages of being easy to perform anti-interference treatment on the signal; the method is strong in diversified impulse signal adaptation and high in power angle measuring precision.